xref: /openbmc/linux/drivers/acpi/tables.c (revision 842ed298)
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 	table_end = (unsigned long)table_header + table_header->length;
296 
297 	/* Parse all entries looking for a match. */
298 
299 	entry.type = acpi_get_subtable_type(id);
300 	entry.hdr = (union acpi_subtable_headers *)
301 	    ((unsigned long)table_header + table_size);
302 	subtable_len = acpi_get_subtable_header_length(&entry);
303 
304 	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
305 		if (max_entries && count >= max_entries)
306 			break;
307 
308 		for (i = 0; i < proc_num; i++) {
309 			if (acpi_get_entry_type(&entry) != proc[i].id)
310 				continue;
311 			if (!proc[i].handler ||
312 			     (!errs && proc[i].handler(entry.hdr, table_end))) {
313 				errs++;
314 				continue;
315 			}
316 
317 			proc[i].count++;
318 			break;
319 		}
320 		if (i != proc_num)
321 			count++;
322 
323 		/*
324 		 * If entry->length is 0, break from this loop to avoid
325 		 * infinite loop.
326 		 */
327 		entry_len = acpi_get_entry_length(&entry);
328 		if (entry_len == 0) {
329 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
330 			return -EINVAL;
331 		}
332 
333 		entry.hdr = (union acpi_subtable_headers *)
334 		    ((unsigned long)entry.hdr + entry_len);
335 	}
336 
337 	if (max_entries && count > max_entries) {
338 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
339 			id, proc->id, count);
340 	}
341 
342 	return errs ? -EINVAL : count;
343 }
344 
345 int __init acpi_table_parse_entries_array(char *id,
346 			 unsigned long table_size,
347 			 struct acpi_subtable_proc *proc, int proc_num,
348 			 unsigned int max_entries)
349 {
350 	struct acpi_table_header *table_header = NULL;
351 	int count;
352 	u32 instance = 0;
353 
354 	if (acpi_disabled)
355 		return -ENODEV;
356 
357 	if (!id)
358 		return -EINVAL;
359 
360 	if (!table_size)
361 		return -EINVAL;
362 
363 	if (!strncmp(id, ACPI_SIG_MADT, 4))
364 		instance = acpi_apic_instance;
365 
366 	acpi_get_table(id, instance, &table_header);
367 	if (!table_header) {
368 		pr_warn("%4.4s not present\n", id);
369 		return -ENODEV;
370 	}
371 
372 	count = acpi_parse_entries_array(id, table_size, table_header,
373 			proc, proc_num, max_entries);
374 
375 	acpi_put_table(table_header);
376 	return count;
377 }
378 
379 int __init acpi_table_parse_entries(char *id,
380 			unsigned long table_size,
381 			int entry_id,
382 			acpi_tbl_entry_handler handler,
383 			unsigned int max_entries)
384 {
385 	struct acpi_subtable_proc proc = {
386 		.id		= entry_id,
387 		.handler	= handler,
388 	};
389 
390 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
391 						max_entries);
392 }
393 
394 int __init acpi_table_parse_madt(enum acpi_madt_type id,
395 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
396 {
397 	return acpi_table_parse_entries(ACPI_SIG_MADT,
398 					    sizeof(struct acpi_table_madt), id,
399 					    handler, max_entries);
400 }
401 
402 /**
403  * acpi_table_parse - find table with @id, run @handler on it
404  * @id: table id to find
405  * @handler: handler to run
406  *
407  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
408  * run @handler on it.
409  *
410  * Return 0 if table found, -errno if not.
411  */
412 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
413 {
414 	struct acpi_table_header *table = NULL;
415 
416 	if (acpi_disabled)
417 		return -ENODEV;
418 
419 	if (!id || !handler)
420 		return -EINVAL;
421 
422 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
423 		acpi_get_table(id, acpi_apic_instance, &table);
424 	else
425 		acpi_get_table(id, 0, &table);
426 
427 	if (table) {
428 		handler(table);
429 		acpi_put_table(table);
430 		return 0;
431 	} else
432 		return -ENODEV;
433 }
434 
435 /*
436  * The BIOS is supposed to supply a single APIC/MADT,
437  * but some report two.  Provide a knob to use either.
438  * (don't you wish instance 0 and 1 were not the same?)
439  */
440 static void __init check_multiple_madt(void)
441 {
442 	struct acpi_table_header *table = NULL;
443 
444 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
445 	if (table) {
446 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
447 			acpi_apic_instance);
448 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
449 			"notify linux-acpi@vger.kernel.org\n",
450 			acpi_apic_instance ? 0 : 2);
451 		acpi_put_table(table);
452 
453 	} else
454 		acpi_apic_instance = 0;
455 
456 	return;
457 }
458 
459 static void acpi_table_taint(struct acpi_table_header *table)
460 {
461 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
462 		table->signature, table->oem_table_id);
463 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
464 }
465 
466 #ifdef CONFIG_ACPI_TABLE_UPGRADE
467 static u64 acpi_tables_addr;
468 static int all_tables_size;
469 
470 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
471 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
472 {
473 	u8 sum = 0;
474 	u8 *end = buffer + length;
475 
476 	while (buffer < end)
477 		sum = (u8) (sum + *(buffer++));
478 	return sum;
479 }
480 
481 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
482 static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
483 	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
484 	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
485 	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
486 	ACPI_SIG_ASF,  ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
487 	ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
488 	ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
489 	ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
490 	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
491 	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
492 	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
493 	ACPI_SIG_NHLT };
494 
495 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
496 
497 #define NR_ACPI_INITRD_TABLES 64
498 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
499 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
500 
501 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
502 
503 void __init acpi_table_upgrade(void)
504 {
505 	void *data;
506 	size_t size;
507 	int sig, no, table_nr = 0, total_offset = 0;
508 	long offset = 0;
509 	struct acpi_table_header *table;
510 	char cpio_path[32] = "kernel/firmware/acpi/";
511 	struct cpio_data file;
512 
513 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
514 		data = __initramfs_start;
515 		size = __initramfs_size;
516 	} else {
517 		data = (void *)initrd_start;
518 		size = initrd_end - initrd_start;
519 	}
520 
521 	if (data == NULL || size == 0)
522 		return;
523 
524 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
525 		file = find_cpio_data(cpio_path, data, size, &offset);
526 		if (!file.data)
527 			break;
528 
529 		data += offset;
530 		size -= offset;
531 
532 		if (file.size < sizeof(struct acpi_table_header)) {
533 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
534 				cpio_path, file.name);
535 			continue;
536 		}
537 
538 		table = file.data;
539 
540 		for (sig = 0; sig < ARRAY_SIZE(table_sigs); sig++)
541 			if (!memcmp(table->signature, table_sigs[sig], 4))
542 				break;
543 
544 		if (sig >= ARRAY_SIZE(table_sigs)) {
545 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
546 				cpio_path, file.name);
547 			continue;
548 		}
549 		if (file.size != table->length) {
550 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
551 				cpio_path, file.name);
552 			continue;
553 		}
554 		if (acpi_table_checksum(file.data, table->length)) {
555 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
556 				cpio_path, file.name);
557 			continue;
558 		}
559 
560 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
561 			table->signature, cpio_path, file.name, table->length);
562 
563 		all_tables_size += table->length;
564 		acpi_initrd_files[table_nr].data = file.data;
565 		acpi_initrd_files[table_nr].size = file.size;
566 		table_nr++;
567 	}
568 	if (table_nr == 0)
569 		return;
570 
571 	if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
572 		pr_notice("kernel is locked down, ignoring table override\n");
573 		return;
574 	}
575 
576 	acpi_tables_addr =
577 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
578 				       all_tables_size, PAGE_SIZE);
579 	if (!acpi_tables_addr) {
580 		WARN_ON(1);
581 		return;
582 	}
583 	/*
584 	 * Only calling e820_add_reserve does not work and the
585 	 * tables are invalid (memory got used) later.
586 	 * memblock_reserve works as expected and the tables won't get modified.
587 	 * But it's not enough on X86 because ioremap will
588 	 * complain later (used by acpi_os_map_memory) that the pages
589 	 * that should get mapped are not marked "reserved".
590 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
591 	 * works fine.
592 	 */
593 	memblock_reserve(acpi_tables_addr, all_tables_size);
594 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
595 
596 	/*
597 	 * early_ioremap only can remap 256k one time. If we map all
598 	 * tables one time, we will hit the limit. Need to map chunks
599 	 * one by one during copying the same as that in relocate_initrd().
600 	 */
601 	for (no = 0; no < table_nr; no++) {
602 		unsigned char *src_p = acpi_initrd_files[no].data;
603 		phys_addr_t size = acpi_initrd_files[no].size;
604 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
605 		phys_addr_t slop, clen;
606 		char *dest_p;
607 
608 		total_offset += size;
609 
610 		while (size) {
611 			slop = dest_addr & ~PAGE_MASK;
612 			clen = size;
613 			if (clen > MAP_CHUNK_SIZE - slop)
614 				clen = MAP_CHUNK_SIZE - slop;
615 			dest_p = early_memremap(dest_addr & PAGE_MASK,
616 						clen + slop);
617 			memcpy(dest_p + slop, src_p, clen);
618 			early_memunmap(dest_p, clen + slop);
619 			src_p += clen;
620 			dest_addr += clen;
621 			size -= clen;
622 		}
623 	}
624 }
625 
626 static acpi_status
627 acpi_table_initrd_override(struct acpi_table_header *existing_table,
628 			   acpi_physical_address *address, u32 *length)
629 {
630 	int table_offset = 0;
631 	int table_index = 0;
632 	struct acpi_table_header *table;
633 	u32 table_length;
634 
635 	*length = 0;
636 	*address = 0;
637 	if (!acpi_tables_addr)
638 		return AE_OK;
639 
640 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
641 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
642 					   ACPI_HEADER_SIZE);
643 		if (table_offset + table->length > all_tables_size) {
644 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
645 			WARN_ON(1);
646 			return AE_OK;
647 		}
648 
649 		table_length = table->length;
650 
651 		/* Only override tables matched */
652 		if (memcmp(existing_table->signature, table->signature, 4) ||
653 		    memcmp(table->oem_id, existing_table->oem_id,
654 			   ACPI_OEM_ID_SIZE) ||
655 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
656 			   ACPI_OEM_TABLE_ID_SIZE)) {
657 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
658 			goto next_table;
659 		}
660 		/*
661 		 * Mark the table to avoid being used in
662 		 * acpi_table_initrd_scan() and check the revision.
663 		 */
664 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
665 		    existing_table->oem_revision >= table->oem_revision) {
666 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
667 			goto next_table;
668 		}
669 
670 		*length = table_length;
671 		*address = acpi_tables_addr + table_offset;
672 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
673 			table->signature, table->oem_id,
674 			table->oem_table_id);
675 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
676 		break;
677 
678 next_table:
679 		table_offset += table_length;
680 		table_index++;
681 	}
682 	return AE_OK;
683 }
684 
685 static void __init acpi_table_initrd_scan(void)
686 {
687 	int table_offset = 0;
688 	int table_index = 0;
689 	u32 table_length;
690 	struct acpi_table_header *table;
691 
692 	if (!acpi_tables_addr)
693 		return;
694 
695 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
696 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
697 					   ACPI_HEADER_SIZE);
698 		if (table_offset + table->length > all_tables_size) {
699 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
700 			WARN_ON(1);
701 			return;
702 		}
703 
704 		table_length = table->length;
705 
706 		/* Skip RSDT/XSDT which should only be used for override */
707 		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
708 		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
709 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
710 			goto next_table;
711 		}
712 		/*
713 		 * Mark the table to avoid being used in
714 		 * acpi_table_initrd_override(). Though this is not possible
715 		 * because override is disabled in acpi_install_table().
716 		 */
717 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
718 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
719 			goto next_table;
720 		}
721 
722 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
723 			table->signature, table->oem_id,
724 			table->oem_table_id);
725 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
726 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
727 next_table:
728 		table_offset += table_length;
729 		table_index++;
730 	}
731 }
732 #else
733 static acpi_status
734 acpi_table_initrd_override(struct acpi_table_header *existing_table,
735 			   acpi_physical_address *address,
736 			   u32 *table_length)
737 {
738 	*table_length = 0;
739 	*address = 0;
740 	return AE_OK;
741 }
742 
743 static void __init acpi_table_initrd_scan(void)
744 {
745 }
746 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
747 
748 acpi_status
749 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
750 				acpi_physical_address *address,
751 				u32 *table_length)
752 {
753 	return acpi_table_initrd_override(existing_table, address,
754 					  table_length);
755 }
756 
757 #ifdef CONFIG_ACPI_CUSTOM_DSDT
758 static void *amlcode __attribute__ ((weakref("AmlCode")));
759 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
760 #endif
761 
762 acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
763 		       struct acpi_table_header **new_table)
764 {
765 	if (!existing_table || !new_table)
766 		return AE_BAD_PARAMETER;
767 
768 	*new_table = NULL;
769 
770 #ifdef CONFIG_ACPI_CUSTOM_DSDT
771 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
772 		*new_table = (struct acpi_table_header *)&amlcode;
773 		if (!(*new_table))
774 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
775 	}
776 #endif
777 	if (*new_table != NULL)
778 		acpi_table_taint(existing_table);
779 	return AE_OK;
780 }
781 
782 /*
783  * acpi_table_init()
784  *
785  * find RSDP, find and checksum SDT/XSDT.
786  * checksum all tables, print SDT/XSDT
787  *
788  * result: sdt_entry[] is initialized
789  */
790 
791 int __init acpi_table_init(void)
792 {
793 	acpi_status status;
794 
795 	if (acpi_verify_table_checksum) {
796 		pr_info("Early table checksum verification enabled\n");
797 		acpi_gbl_enable_table_validation = TRUE;
798 	} else {
799 		pr_info("Early table checksum verification disabled\n");
800 		acpi_gbl_enable_table_validation = FALSE;
801 	}
802 
803 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
804 	if (ACPI_FAILURE(status))
805 		return -EINVAL;
806 	acpi_table_initrd_scan();
807 
808 	check_multiple_madt();
809 	return 0;
810 }
811 
812 static int __init acpi_parse_apic_instance(char *str)
813 {
814 	if (!str)
815 		return -EINVAL;
816 
817 	if (kstrtoint(str, 0, &acpi_apic_instance))
818 		return -EINVAL;
819 
820 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
821 
822 	return 0;
823 }
824 early_param("acpi_apic_instance", acpi_parse_apic_instance);
825 
826 static int __init acpi_force_table_verification_setup(char *s)
827 {
828 	acpi_verify_table_checksum = true;
829 
830 	return 0;
831 }
832 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
833 
834 static int __init acpi_force_32bit_fadt_addr(char *s)
835 {
836 	pr_info("Forcing 32 Bit FADT addresses\n");
837 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
838 
839 	return 0;
840 }
841 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
842