xref: /linux/drivers/acpi/tables.c (revision 0e685c3e7158d35626d6d76b9f859eae806d87fa)
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 <linux/kmemleak.h>
25 #include "internal.h"
26 
27 #ifdef CONFIG_ACPI_CUSTOM_DSDT
28 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
29 #endif
30 
31 #define ACPI_MAX_TABLES		128
32 
33 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
34 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
35 
36 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
37 
38 static int acpi_apic_instance __initdata_or_acpilib;
39 
40 enum acpi_subtable_type {
41 	ACPI_SUBTABLE_COMMON,
42 	ACPI_SUBTABLE_HMAT,
43 	ACPI_SUBTABLE_PRMT,
44 	ACPI_SUBTABLE_CEDT,
45 };
46 
47 struct acpi_subtable_entry {
48 	union acpi_subtable_headers *hdr;
49 	enum acpi_subtable_type type;
50 };
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_or_acpilib = 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[0x%llx])\n",
155 				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 	case ACPI_MADT_TYPE_CORE_PIC:
214 		{
215 			struct acpi_madt_core_pic *p = (struct acpi_madt_core_pic *)header;
216 
217 			pr_debug("CORE PIC (processor_id[0x%02x] core_id[0x%02x] %s)\n",
218 				 p->processor_id, p->core_id,
219 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
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_or_acpilib
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 	case ACPI_SUBTABLE_PRMT:
239 		return 0;
240 	case ACPI_SUBTABLE_CEDT:
241 		return entry->hdr->cedt.type;
242 	}
243 	return 0;
244 }
245 
246 static unsigned long __init_or_acpilib
247 acpi_get_entry_length(struct acpi_subtable_entry *entry)
248 {
249 	switch (entry->type) {
250 	case ACPI_SUBTABLE_COMMON:
251 		return entry->hdr->common.length;
252 	case ACPI_SUBTABLE_HMAT:
253 		return entry->hdr->hmat.length;
254 	case ACPI_SUBTABLE_PRMT:
255 		return entry->hdr->prmt.length;
256 	case ACPI_SUBTABLE_CEDT:
257 		return entry->hdr->cedt.length;
258 	}
259 	return 0;
260 }
261 
262 static unsigned long __init_or_acpilib
263 acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
264 {
265 	switch (entry->type) {
266 	case ACPI_SUBTABLE_COMMON:
267 		return sizeof(entry->hdr->common);
268 	case ACPI_SUBTABLE_HMAT:
269 		return sizeof(entry->hdr->hmat);
270 	case ACPI_SUBTABLE_PRMT:
271 		return sizeof(entry->hdr->prmt);
272 	case ACPI_SUBTABLE_CEDT:
273 		return sizeof(entry->hdr->cedt);
274 	}
275 	return 0;
276 }
277 
278 static enum acpi_subtable_type __init_or_acpilib
279 acpi_get_subtable_type(char *id)
280 {
281 	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
282 		return ACPI_SUBTABLE_HMAT;
283 	if (strncmp(id, ACPI_SIG_PRMT, 4) == 0)
284 		return ACPI_SUBTABLE_PRMT;
285 	if (strncmp(id, ACPI_SIG_CEDT, 4) == 0)
286 		return ACPI_SUBTABLE_CEDT;
287 	return ACPI_SUBTABLE_COMMON;
288 }
289 
290 static __init_or_acpilib bool has_handler(struct acpi_subtable_proc *proc)
291 {
292 	return proc->handler || proc->handler_arg;
293 }
294 
295 static __init_or_acpilib int call_handler(struct acpi_subtable_proc *proc,
296 					  union acpi_subtable_headers *hdr,
297 					  unsigned long end)
298 {
299 	if (proc->handler)
300 		return proc->handler(hdr, end);
301 	if (proc->handler_arg)
302 		return proc->handler_arg(hdr, proc->arg, end);
303 	return -EINVAL;
304 }
305 
306 /**
307  * acpi_parse_entries_array - for each proc_num find a suitable subtable
308  *
309  * @id: table id (for debugging purposes)
310  * @table_size: size of the root table
311  * @table_header: where does the table start?
312  * @proc: array of acpi_subtable_proc struct containing entry id
313  *        and associated handler with it
314  * @proc_num: how big proc is?
315  * @max_entries: how many entries can we process?
316  *
317  * For each proc_num find a subtable with proc->id and run proc->handler
318  * on it. Assumption is that there's only single handler for particular
319  * entry id.
320  *
321  * The table_size is not the size of the complete ACPI table (the length
322  * field in the header struct), but only the size of the root table; i.e.,
323  * the offset from the very first byte of the complete ACPI table, to the
324  * first byte of the very first subtable.
325  *
326  * On success returns sum of all matching entries for all proc handlers.
327  * Otherwise, -ENODEV or -EINVAL is returned.
328  */
329 static int __init_or_acpilib acpi_parse_entries_array(
330 	char *id, unsigned long table_size,
331 	struct acpi_table_header *table_header, struct acpi_subtable_proc *proc,
332 	int proc_num, unsigned int max_entries)
333 {
334 	struct acpi_subtable_entry entry;
335 	unsigned long table_end, subtable_len, entry_len;
336 	int count = 0;
337 	int errs = 0;
338 	int i;
339 
340 	table_end = (unsigned long)table_header + table_header->length;
341 
342 	/* Parse all entries looking for a match. */
343 
344 	entry.type = acpi_get_subtable_type(id);
345 	entry.hdr = (union acpi_subtable_headers *)
346 	    ((unsigned long)table_header + table_size);
347 	subtable_len = acpi_get_subtable_header_length(&entry);
348 
349 	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
350 		if (max_entries && count >= max_entries)
351 			break;
352 
353 		for (i = 0; i < proc_num; i++) {
354 			if (acpi_get_entry_type(&entry) != proc[i].id)
355 				continue;
356 			if (!has_handler(&proc[i]) ||
357 			    (!errs &&
358 			     call_handler(&proc[i], entry.hdr, table_end))) {
359 				errs++;
360 				continue;
361 			}
362 
363 			proc[i].count++;
364 			break;
365 		}
366 		if (i != proc_num)
367 			count++;
368 
369 		/*
370 		 * If entry->length is 0, break from this loop to avoid
371 		 * infinite loop.
372 		 */
373 		entry_len = acpi_get_entry_length(&entry);
374 		if (entry_len == 0) {
375 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
376 			return -EINVAL;
377 		}
378 
379 		entry.hdr = (union acpi_subtable_headers *)
380 		    ((unsigned long)entry.hdr + entry_len);
381 	}
382 
383 	if (max_entries && count > max_entries) {
384 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
385 			id, proc->id, count);
386 	}
387 
388 	return errs ? -EINVAL : count;
389 }
390 
391 int __init_or_acpilib acpi_table_parse_entries_array(
392 	char *id, unsigned long table_size, struct acpi_subtable_proc *proc,
393 	int proc_num, unsigned int max_entries)
394 {
395 	struct acpi_table_header *table_header = NULL;
396 	int count;
397 	u32 instance = 0;
398 
399 	if (acpi_disabled)
400 		return -ENODEV;
401 
402 	if (!id)
403 		return -EINVAL;
404 
405 	if (!table_size)
406 		return -EINVAL;
407 
408 	if (!strncmp(id, ACPI_SIG_MADT, 4))
409 		instance = acpi_apic_instance;
410 
411 	acpi_get_table(id, instance, &table_header);
412 	if (!table_header) {
413 		pr_debug("%4.4s not present\n", id);
414 		return -ENODEV;
415 	}
416 
417 	count = acpi_parse_entries_array(id, table_size, table_header,
418 			proc, proc_num, max_entries);
419 
420 	acpi_put_table(table_header);
421 	return count;
422 }
423 
424 static int __init_or_acpilib __acpi_table_parse_entries(
425 	char *id, unsigned long table_size, int entry_id,
426 	acpi_tbl_entry_handler handler, acpi_tbl_entry_handler_arg handler_arg,
427 	void *arg, unsigned int max_entries)
428 {
429 	struct acpi_subtable_proc proc = {
430 		.id		= entry_id,
431 		.handler	= handler,
432 		.handler_arg	= handler_arg,
433 		.arg		= arg,
434 	};
435 
436 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
437 						max_entries);
438 }
439 
440 int __init_or_acpilib
441 acpi_table_parse_cedt(enum acpi_cedt_type id,
442 		      acpi_tbl_entry_handler_arg handler_arg, void *arg)
443 {
444 	return __acpi_table_parse_entries(ACPI_SIG_CEDT,
445 					  sizeof(struct acpi_table_cedt), id,
446 					  NULL, handler_arg, arg, 0);
447 }
448 EXPORT_SYMBOL_ACPI_LIB(acpi_table_parse_cedt);
449 
450 int __init acpi_table_parse_entries(char *id, unsigned long table_size,
451 				    int entry_id,
452 				    acpi_tbl_entry_handler handler,
453 				    unsigned int max_entries)
454 {
455 	return __acpi_table_parse_entries(id, table_size, entry_id, handler,
456 					  NULL, NULL, max_entries);
457 }
458 
459 int __init acpi_table_parse_madt(enum acpi_madt_type id,
460 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
461 {
462 	return acpi_table_parse_entries(ACPI_SIG_MADT,
463 					    sizeof(struct acpi_table_madt), id,
464 					    handler, max_entries);
465 }
466 
467 /**
468  * acpi_table_parse - find table with @id, run @handler on it
469  * @id: table id to find
470  * @handler: handler to run
471  *
472  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
473  * run @handler on it.
474  *
475  * Return 0 if table found, -errno if not.
476  */
477 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
478 {
479 	struct acpi_table_header *table = NULL;
480 
481 	if (acpi_disabled)
482 		return -ENODEV;
483 
484 	if (!id || !handler)
485 		return -EINVAL;
486 
487 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
488 		acpi_get_table(id, acpi_apic_instance, &table);
489 	else
490 		acpi_get_table(id, 0, &table);
491 
492 	if (table) {
493 		handler(table);
494 		acpi_put_table(table);
495 		return 0;
496 	} else
497 		return -ENODEV;
498 }
499 
500 /*
501  * The BIOS is supposed to supply a single APIC/MADT,
502  * but some report two.  Provide a knob to use either.
503  * (don't you wish instance 0 and 1 were not the same?)
504  */
505 static void __init check_multiple_madt(void)
506 {
507 	struct acpi_table_header *table = NULL;
508 
509 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
510 	if (table) {
511 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
512 			acpi_apic_instance);
513 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
514 			"notify linux-acpi@vger.kernel.org\n",
515 			acpi_apic_instance ? 0 : 2);
516 		acpi_put_table(table);
517 
518 	} else
519 		acpi_apic_instance = 0;
520 
521 	return;
522 }
523 
524 static void acpi_table_taint(struct acpi_table_header *table)
525 {
526 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
527 		table->signature, table->oem_table_id);
528 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
529 }
530 
531 #ifdef CONFIG_ACPI_TABLE_UPGRADE
532 static u64 acpi_tables_addr;
533 static int all_tables_size;
534 
535 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
536 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
537 {
538 	u8 sum = 0;
539 	u8 *end = buffer + length;
540 
541 	while (buffer < end)
542 		sum = (u8) (sum + *(buffer++));
543 	return sum;
544 }
545 
546 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
547 static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
548 	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
549 	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
550 	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
551 	ACPI_SIG_ASF,  ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
552 	ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
553 	ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
554 	ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
555 	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
556 	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
557 	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
558 	ACPI_SIG_NHLT, ACPI_SIG_AEST, ACPI_SIG_CEDT, ACPI_SIG_AGDI,
559 	ACPI_SIG_NBFT };
560 
561 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
562 
563 #define NR_ACPI_INITRD_TABLES 64
564 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
565 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
566 
567 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
568 
569 void __init acpi_table_upgrade(void)
570 {
571 	void *data;
572 	size_t size;
573 	int sig, no, table_nr = 0, total_offset = 0;
574 	long offset = 0;
575 	struct acpi_table_header *table;
576 	char cpio_path[32] = "kernel/firmware/acpi/";
577 	struct cpio_data file;
578 
579 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
580 		data = __initramfs_start;
581 		size = __initramfs_size;
582 	} else {
583 		data = (void *)initrd_start;
584 		size = initrd_end - initrd_start;
585 	}
586 
587 	if (data == NULL || size == 0)
588 		return;
589 
590 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
591 		file = find_cpio_data(cpio_path, data, size, &offset);
592 		if (!file.data)
593 			break;
594 
595 		data += offset;
596 		size -= offset;
597 
598 		if (file.size < sizeof(struct acpi_table_header)) {
599 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
600 				cpio_path, file.name);
601 			continue;
602 		}
603 
604 		table = file.data;
605 
606 		for (sig = 0; sig < ARRAY_SIZE(table_sigs); sig++)
607 			if (!memcmp(table->signature, table_sigs[sig], 4))
608 				break;
609 
610 		if (sig >= ARRAY_SIZE(table_sigs)) {
611 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
612 				cpio_path, file.name);
613 			continue;
614 		}
615 		if (file.size != table->length) {
616 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
617 				cpio_path, file.name);
618 			continue;
619 		}
620 		if (acpi_table_checksum(file.data, table->length)) {
621 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
622 				cpio_path, file.name);
623 			continue;
624 		}
625 
626 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
627 			table->signature, cpio_path, file.name, table->length);
628 
629 		all_tables_size += table->length;
630 		acpi_initrd_files[table_nr].data = file.data;
631 		acpi_initrd_files[table_nr].size = file.size;
632 		table_nr++;
633 	}
634 	if (table_nr == 0)
635 		return;
636 
637 	if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
638 		pr_notice("kernel is locked down, ignoring table override\n");
639 		return;
640 	}
641 
642 	acpi_tables_addr =
643 		memblock_phys_alloc_range(all_tables_size, PAGE_SIZE,
644 					  0, ACPI_TABLE_UPGRADE_MAX_PHYS);
645 	if (!acpi_tables_addr) {
646 		WARN_ON(1);
647 		return;
648 	}
649 	/*
650 	 * Only calling e820_add_reserve does not work and the
651 	 * tables are invalid (memory got used) later.
652 	 * memblock_reserve works as expected and the tables won't get modified.
653 	 * But it's not enough on X86 because ioremap will
654 	 * complain later (used by acpi_os_map_memory) that the pages
655 	 * that should get mapped are not marked "reserved".
656 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
657 	 * works fine.
658 	 */
659 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
660 
661 	kmemleak_ignore_phys(acpi_tables_addr);
662 
663 	/*
664 	 * early_ioremap only can remap 256k one time. If we map all
665 	 * tables one time, we will hit the limit. Need to map chunks
666 	 * one by one during copying the same as that in relocate_initrd().
667 	 */
668 	for (no = 0; no < table_nr; no++) {
669 		unsigned char *src_p = acpi_initrd_files[no].data;
670 		phys_addr_t size = acpi_initrd_files[no].size;
671 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
672 		phys_addr_t slop, clen;
673 		char *dest_p;
674 
675 		total_offset += size;
676 
677 		while (size) {
678 			slop = dest_addr & ~PAGE_MASK;
679 			clen = size;
680 			if (clen > MAP_CHUNK_SIZE - slop)
681 				clen = MAP_CHUNK_SIZE - slop;
682 			dest_p = early_memremap(dest_addr & PAGE_MASK,
683 						clen + slop);
684 			memcpy(dest_p + slop, src_p, clen);
685 			early_memunmap(dest_p, clen + slop);
686 			src_p += clen;
687 			dest_addr += clen;
688 			size -= clen;
689 		}
690 	}
691 }
692 
693 static acpi_status
694 acpi_table_initrd_override(struct acpi_table_header *existing_table,
695 			   acpi_physical_address *address, u32 *length)
696 {
697 	int table_offset = 0;
698 	int table_index = 0;
699 	struct acpi_table_header *table;
700 	u32 table_length;
701 
702 	*length = 0;
703 	*address = 0;
704 	if (!acpi_tables_addr)
705 		return AE_OK;
706 
707 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
708 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
709 					   ACPI_HEADER_SIZE);
710 		if (table_offset + table->length > all_tables_size) {
711 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
712 			WARN_ON(1);
713 			return AE_OK;
714 		}
715 
716 		table_length = table->length;
717 
718 		/* Only override tables matched */
719 		if (memcmp(existing_table->signature, table->signature, 4) ||
720 		    memcmp(table->oem_id, existing_table->oem_id,
721 			   ACPI_OEM_ID_SIZE) ||
722 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
723 			   ACPI_OEM_TABLE_ID_SIZE)) {
724 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
725 			goto next_table;
726 		}
727 		/*
728 		 * Mark the table to avoid being used in
729 		 * acpi_table_initrd_scan() and check the revision.
730 		 */
731 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
732 		    existing_table->oem_revision >= table->oem_revision) {
733 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
734 			goto next_table;
735 		}
736 
737 		*length = table_length;
738 		*address = acpi_tables_addr + table_offset;
739 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
740 			table->signature, table->oem_id,
741 			table->oem_table_id);
742 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
743 		break;
744 
745 next_table:
746 		table_offset += table_length;
747 		table_index++;
748 	}
749 	return AE_OK;
750 }
751 
752 static void __init acpi_table_initrd_scan(void)
753 {
754 	int table_offset = 0;
755 	int table_index = 0;
756 	u32 table_length;
757 	struct acpi_table_header *table;
758 
759 	if (!acpi_tables_addr)
760 		return;
761 
762 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
763 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
764 					   ACPI_HEADER_SIZE);
765 		if (table_offset + table->length > all_tables_size) {
766 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
767 			WARN_ON(1);
768 			return;
769 		}
770 
771 		table_length = table->length;
772 
773 		/* Skip RSDT/XSDT which should only be used for override */
774 		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
775 		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
776 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
777 			goto next_table;
778 		}
779 		/*
780 		 * Mark the table to avoid being used in
781 		 * acpi_table_initrd_override(). Though this is not possible
782 		 * because override is disabled in acpi_install_physical_table().
783 		 */
784 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
785 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
786 			goto next_table;
787 		}
788 
789 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
790 			table->signature, table->oem_id,
791 			table->oem_table_id);
792 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
793 		acpi_install_physical_table(acpi_tables_addr + table_offset);
794 next_table:
795 		table_offset += table_length;
796 		table_index++;
797 	}
798 }
799 #else
800 static acpi_status
801 acpi_table_initrd_override(struct acpi_table_header *existing_table,
802 			   acpi_physical_address *address,
803 			   u32 *table_length)
804 {
805 	*table_length = 0;
806 	*address = 0;
807 	return AE_OK;
808 }
809 
810 static void __init acpi_table_initrd_scan(void)
811 {
812 }
813 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
814 
815 acpi_status
816 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
817 				acpi_physical_address *address,
818 				u32 *table_length)
819 {
820 	return acpi_table_initrd_override(existing_table, address,
821 					  table_length);
822 }
823 
824 #ifdef CONFIG_ACPI_CUSTOM_DSDT
825 static void *amlcode __attribute__ ((weakref("AmlCode")));
826 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
827 #endif
828 
829 acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
830 		       struct acpi_table_header **new_table)
831 {
832 	if (!existing_table || !new_table)
833 		return AE_BAD_PARAMETER;
834 
835 	*new_table = NULL;
836 
837 #ifdef CONFIG_ACPI_CUSTOM_DSDT
838 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
839 		*new_table = (struct acpi_table_header *)&amlcode;
840 		if (!(*new_table))
841 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
842 	}
843 #endif
844 	if (*new_table != NULL)
845 		acpi_table_taint(existing_table);
846 	return AE_OK;
847 }
848 
849 /*
850  * acpi_locate_initial_tables()
851  *
852  * Get the RSDP, then find and checksum all the ACPI tables.
853  *
854  * result: initial_tables[] is initialized, and points to
855  * a list of ACPI tables.
856  */
857 int __init acpi_locate_initial_tables(void)
858 {
859 	acpi_status status;
860 
861 	if (acpi_verify_table_checksum) {
862 		pr_info("Early table checksum verification enabled\n");
863 		acpi_gbl_enable_table_validation = TRUE;
864 	} else {
865 		pr_info("Early table checksum verification disabled\n");
866 		acpi_gbl_enable_table_validation = FALSE;
867 	}
868 
869 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
870 	if (ACPI_FAILURE(status))
871 		return -EINVAL;
872 
873 	return 0;
874 }
875 
876 void __init acpi_reserve_initial_tables(void)
877 {
878 	int i;
879 
880 	for (i = 0; i < ACPI_MAX_TABLES; i++) {
881 		struct acpi_table_desc *table_desc = &initial_tables[i];
882 		u64 start = table_desc->address;
883 		u64 size = table_desc->length;
884 
885 		if (!start || !size)
886 			break;
887 
888 		pr_info("Reserving %4s table memory at [mem 0x%llx-0x%llx]\n",
889 			table_desc->signature.ascii, start, start + size - 1);
890 
891 		memblock_reserve(start, size);
892 	}
893 }
894 
895 void __init acpi_table_init_complete(void)
896 {
897 	acpi_table_initrd_scan();
898 	check_multiple_madt();
899 }
900 
901 int __init acpi_table_init(void)
902 {
903 	int ret;
904 
905 	ret = acpi_locate_initial_tables();
906 	if (ret)
907 		return ret;
908 
909 	acpi_table_init_complete();
910 
911 	return 0;
912 }
913 
914 static int __init acpi_parse_apic_instance(char *str)
915 {
916 	if (!str)
917 		return -EINVAL;
918 
919 	if (kstrtoint(str, 0, &acpi_apic_instance))
920 		return -EINVAL;
921 
922 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
923 
924 	return 0;
925 }
926 early_param("acpi_apic_instance", acpi_parse_apic_instance);
927 
928 static int __init acpi_force_table_verification_setup(char *s)
929 {
930 	acpi_verify_table_checksum = true;
931 
932 	return 0;
933 }
934 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
935 
936 static int __init acpi_force_32bit_fadt_addr(char *s)
937 {
938 	pr_info("Forcing 32 Bit FADT addresses\n");
939 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
940 
941 	return 0;
942 }
943 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
944