m68k: Migrate exception table users off module.h and onto extable.h
[platform/kernel/linux-exynos.git] / drivers / acpi / tables.c
1 /*
2  *  acpi_tables.c - ACPI Boot-Time Table Parsing
3  *
4  *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19  *
20  */
21
22 /* Uncomment next line to get verbose printout */
23 /* #define DEBUG */
24 #define pr_fmt(fmt) "ACPI: " fmt
25
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/smp.h>
29 #include <linux/string.h>
30 #include <linux/types.h>
31 #include <linux/irq.h>
32 #include <linux/errno.h>
33 #include <linux/acpi.h>
34 #include <linux/bootmem.h>
35 #include <linux/earlycpio.h>
36 #include <linux/memblock.h>
37 #include <linux/initrd.h>
38 #include <linux/acpi.h>
39 #include "internal.h"
40
41 #ifdef CONFIG_ACPI_CUSTOM_DSDT
42 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
43 #endif
44
45 #define ACPI_MAX_TABLES         128
46
47 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
48 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
49
50 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
51
52 static int acpi_apic_instance __initdata;
53
54 /*
55  * Disable table checksum verification for the early stage due to the size
56  * limitation of the current x86 early mapping implementation.
57  */
58 static bool acpi_verify_table_checksum __initdata = false;
59
60 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
61 {
62         if (!header)
63                 return;
64
65         switch (header->type) {
66
67         case ACPI_MADT_TYPE_LOCAL_APIC:
68                 {
69                         struct acpi_madt_local_apic *p =
70                             (struct acpi_madt_local_apic *)header;
71                         pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
72                                  p->processor_id, p->id,
73                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
74                 }
75                 break;
76
77         case ACPI_MADT_TYPE_LOCAL_X2APIC:
78                 {
79                         struct acpi_madt_local_x2apic *p =
80                             (struct acpi_madt_local_x2apic *)header;
81                         pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
82                                  p->local_apic_id, p->uid,
83                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
84                 }
85                 break;
86
87         case ACPI_MADT_TYPE_IO_APIC:
88                 {
89                         struct acpi_madt_io_apic *p =
90                             (struct acpi_madt_io_apic *)header;
91                         pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
92                                  p->id, p->address, p->global_irq_base);
93                 }
94                 break;
95
96         case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
97                 {
98                         struct acpi_madt_interrupt_override *p =
99                             (struct acpi_madt_interrupt_override *)header;
100                         pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
101                                 p->bus, p->source_irq, p->global_irq,
102                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
103                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
104                         if (p->inti_flags  &
105                             ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
106                                 pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
107                                         p->inti_flags  &
108                                         ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
109                 }
110                 break;
111
112         case ACPI_MADT_TYPE_NMI_SOURCE:
113                 {
114                         struct acpi_madt_nmi_source *p =
115                             (struct acpi_madt_nmi_source *)header;
116                         pr_info("NMI_SRC (%s %s global_irq %d)\n",
117                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
118                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
119                                 p->global_irq);
120                 }
121                 break;
122
123         case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
124                 {
125                         struct acpi_madt_local_apic_nmi *p =
126                             (struct acpi_madt_local_apic_nmi *)header;
127                         pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
128                                 p->processor_id,
129                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK ],
130                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
131                                 p->lint);
132                 }
133                 break;
134
135         case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
136                 {
137                         u16 polarity, trigger;
138                         struct acpi_madt_local_x2apic_nmi *p =
139                             (struct acpi_madt_local_x2apic_nmi *)header;
140
141                         polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
142                         trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
143
144                         pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
145                                 p->uid,
146                                 mps_inti_flags_polarity[polarity],
147                                 mps_inti_flags_trigger[trigger],
148                                 p->lint);
149                 }
150                 break;
151
152         case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
153                 {
154                         struct acpi_madt_local_apic_override *p =
155                             (struct acpi_madt_local_apic_override *)header;
156                         pr_info("LAPIC_ADDR_OVR (address[%p])\n",
157                                 (void *)(unsigned long)p->address);
158                 }
159                 break;
160
161         case ACPI_MADT_TYPE_IO_SAPIC:
162                 {
163                         struct acpi_madt_io_sapic *p =
164                             (struct acpi_madt_io_sapic *)header;
165                         pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
166                                  p->id, (void *)(unsigned long)p->address,
167                                  p->global_irq_base);
168                 }
169                 break;
170
171         case ACPI_MADT_TYPE_LOCAL_SAPIC:
172                 {
173                         struct acpi_madt_local_sapic *p =
174                             (struct acpi_madt_local_sapic *)header;
175                         pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
176                                  p->processor_id, p->id, p->eid,
177                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
178                 }
179                 break;
180
181         case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
182                 {
183                         struct acpi_madt_interrupt_source *p =
184                             (struct acpi_madt_interrupt_source *)header;
185                         pr_info("PLAT_INT_SRC (%s %s type[0x%x] id[0x%04x] eid[0x%x] iosapic_vector[0x%x] global_irq[0x%x]\n",
186                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
187                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
188                                 p->type, p->id, p->eid, p->io_sapic_vector,
189                                 p->global_irq);
190                 }
191                 break;
192
193         case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
194                 {
195                         struct acpi_madt_generic_interrupt *p =
196                                 (struct acpi_madt_generic_interrupt *)header;
197                         pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
198                                  p->uid, p->base_address,
199                                  p->arm_mpidr,
200                                  (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
201
202                 }
203                 break;
204
205         case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
206                 {
207                         struct acpi_madt_generic_distributor *p =
208                                 (struct acpi_madt_generic_distributor *)header;
209                         pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
210                                  p->gic_id, p->base_address,
211                                  p->global_irq_base);
212                 }
213                 break;
214
215         default:
216                 pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
217                         header->type);
218                 break;
219         }
220 }
221
222 /**
223  * acpi_parse_entries_array - for each proc_num find a suitable subtable
224  *
225  * @id: table id (for debugging purposes)
226  * @table_size: single entry size
227  * @table_header: where does the table start?
228  * @proc: array of acpi_subtable_proc struct containing entry id
229  *        and associated handler with it
230  * @proc_num: how big proc is?
231  * @max_entries: how many entries can we process?
232  *
233  * For each proc_num find a subtable with proc->id and run proc->handler
234  * on it. Assumption is that there's only single handler for particular
235  * entry id.
236  *
237  * On success returns sum of all matching entries for all proc handlers.
238  * Otherwise, -ENODEV or -EINVAL is returned.
239  */
240 static int __init
241 acpi_parse_entries_array(char *id, unsigned long table_size,
242                 struct acpi_table_header *table_header,
243                 struct acpi_subtable_proc *proc, int proc_num,
244                 unsigned int max_entries)
245 {
246         struct acpi_subtable_header *entry;
247         unsigned long table_end;
248         int count = 0;
249         int i;
250
251         if (acpi_disabled)
252                 return -ENODEV;
253
254         if (!id)
255                 return -EINVAL;
256
257         if (!table_size)
258                 return -EINVAL;
259
260         if (!table_header) {
261                 pr_warn("%4.4s not present\n", id);
262                 return -ENODEV;
263         }
264
265         table_end = (unsigned long)table_header + table_header->length;
266
267         /* Parse all entries looking for a match. */
268
269         entry = (struct acpi_subtable_header *)
270             ((unsigned long)table_header + table_size);
271
272         while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
273                table_end) {
274                 if (max_entries && count >= max_entries)
275                         break;
276
277                 for (i = 0; i < proc_num; i++) {
278                         if (entry->type != proc[i].id)
279                                 continue;
280                         if (!proc[i].handler ||
281                              proc[i].handler(entry, table_end))
282                                 return -EINVAL;
283
284                         proc->count++;
285                         break;
286                 }
287                 if (i != proc_num)
288                         count++;
289
290                 /*
291                  * If entry->length is 0, break from this loop to avoid
292                  * infinite loop.
293                  */
294                 if (entry->length == 0) {
295                         pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
296                         return -EINVAL;
297                 }
298
299                 entry = (struct acpi_subtable_header *)
300                     ((unsigned long)entry + entry->length);
301         }
302
303         if (max_entries && count > max_entries) {
304                 pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
305                         id, proc->id, count - max_entries, count);
306         }
307
308         return count;
309 }
310
311 int __init
312 acpi_parse_entries(char *id,
313                         unsigned long table_size,
314                         acpi_tbl_entry_handler handler,
315                         struct acpi_table_header *table_header,
316                         int entry_id, unsigned int max_entries)
317 {
318         struct acpi_subtable_proc proc = {
319                 .id             = entry_id,
320                 .handler        = handler,
321         };
322
323         return acpi_parse_entries_array(id, table_size, table_header,
324                         &proc, 1, max_entries);
325 }
326
327 int __init
328 acpi_table_parse_entries_array(char *id,
329                          unsigned long table_size,
330                          struct acpi_subtable_proc *proc, int proc_num,
331                          unsigned int max_entries)
332 {
333         struct acpi_table_header *table_header = NULL;
334         acpi_size tbl_size;
335         int count;
336         u32 instance = 0;
337
338         if (acpi_disabled)
339                 return -ENODEV;
340
341         if (!id)
342                 return -EINVAL;
343
344         if (!strncmp(id, ACPI_SIG_MADT, 4))
345                 instance = acpi_apic_instance;
346
347         acpi_get_table_with_size(id, instance, &table_header, &tbl_size);
348         if (!table_header) {
349                 pr_warn("%4.4s not present\n", id);
350                 return -ENODEV;
351         }
352
353         count = acpi_parse_entries_array(id, table_size, table_header,
354                         proc, proc_num, max_entries);
355
356         early_acpi_os_unmap_memory((char *)table_header, tbl_size);
357         return count;
358 }
359
360 int __init
361 acpi_table_parse_entries(char *id,
362                         unsigned long table_size,
363                         int entry_id,
364                         acpi_tbl_entry_handler handler,
365                         unsigned int max_entries)
366 {
367         struct acpi_subtable_proc proc = {
368                 .id             = entry_id,
369                 .handler        = handler,
370         };
371
372         return acpi_table_parse_entries_array(id, table_size, &proc, 1,
373                                                 max_entries);
374 }
375
376 int __init
377 acpi_table_parse_madt(enum acpi_madt_type id,
378                       acpi_tbl_entry_handler handler, unsigned int max_entries)
379 {
380         return acpi_table_parse_entries(ACPI_SIG_MADT,
381                                             sizeof(struct acpi_table_madt), id,
382                                             handler, max_entries);
383 }
384
385 /**
386  * acpi_table_parse - find table with @id, run @handler on it
387  * @id: table id to find
388  * @handler: handler to run
389  *
390  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
391  * run @handler on it.
392  *
393  * Return 0 if table found, -errno if not.
394  */
395 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
396 {
397         struct acpi_table_header *table = NULL;
398         acpi_size tbl_size;
399
400         if (acpi_disabled)
401                 return -ENODEV;
402
403         if (!id || !handler)
404                 return -EINVAL;
405
406         if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
407                 acpi_get_table_with_size(id, acpi_apic_instance, &table, &tbl_size);
408         else
409                 acpi_get_table_with_size(id, 0, &table, &tbl_size);
410
411         if (table) {
412                 handler(table);
413                 early_acpi_os_unmap_memory(table, tbl_size);
414                 return 0;
415         } else
416                 return -ENODEV;
417 }
418
419 /* 
420  * The BIOS is supposed to supply a single APIC/MADT,
421  * but some report two.  Provide a knob to use either.
422  * (don't you wish instance 0 and 1 were not the same?)
423  */
424 static void __init check_multiple_madt(void)
425 {
426         struct acpi_table_header *table = NULL;
427         acpi_size tbl_size;
428
429         acpi_get_table_with_size(ACPI_SIG_MADT, 2, &table, &tbl_size);
430         if (table) {
431                 pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
432                         acpi_apic_instance);
433                 pr_warn("If \"acpi_apic_instance=%d\" works better, "
434                         "notify linux-acpi@vger.kernel.org\n",
435                         acpi_apic_instance ? 0 : 2);
436                 early_acpi_os_unmap_memory(table, tbl_size);
437
438         } else
439                 acpi_apic_instance = 0;
440
441         return;
442 }
443
444 static void acpi_table_taint(struct acpi_table_header *table)
445 {
446         pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
447                 table->signature, table->oem_table_id);
448         add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
449 }
450
451 #ifdef CONFIG_ACPI_TABLE_UPGRADE
452 static u64 acpi_tables_addr;
453 static int all_tables_size;
454
455 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
456 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
457 {
458         u8 sum = 0;
459         u8 *end = buffer + length;
460
461         while (buffer < end)
462                 sum = (u8) (sum + *(buffer++));
463         return sum;
464 }
465
466 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
467 static const char * const table_sigs[] = {
468         ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
469         ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
470         ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
471         ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
472         ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
473         ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
474         ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
475         ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
476         ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
477
478 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
479
480 #define NR_ACPI_INITRD_TABLES 64
481 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
482 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
483
484 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
485
486 void __init acpi_table_upgrade(void)
487 {
488         void *data = (void *)initrd_start;
489         size_t size = initrd_end - initrd_start;
490         int sig, no, table_nr = 0, total_offset = 0;
491         long offset = 0;
492         struct acpi_table_header *table;
493         char cpio_path[32] = "kernel/firmware/acpi/";
494         struct cpio_data file;
495
496         if (data == NULL || size == 0)
497                 return;
498
499         for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
500                 file = find_cpio_data(cpio_path, data, size, &offset);
501                 if (!file.data)
502                         break;
503
504                 data += offset;
505                 size -= offset;
506
507                 if (file.size < sizeof(struct acpi_table_header)) {
508                         pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
509                                 cpio_path, file.name);
510                         continue;
511                 }
512
513                 table = file.data;
514
515                 for (sig = 0; table_sigs[sig]; sig++)
516                         if (!memcmp(table->signature, table_sigs[sig], 4))
517                                 break;
518
519                 if (!table_sigs[sig]) {
520                         pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
521                                 cpio_path, file.name);
522                         continue;
523                 }
524                 if (file.size != table->length) {
525                         pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
526                                 cpio_path, file.name);
527                         continue;
528                 }
529                 if (acpi_table_checksum(file.data, table->length)) {
530                         pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
531                                 cpio_path, file.name);
532                         continue;
533                 }
534
535                 pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
536                         table->signature, cpio_path, file.name, table->length);
537
538                 all_tables_size += table->length;
539                 acpi_initrd_files[table_nr].data = file.data;
540                 acpi_initrd_files[table_nr].size = file.size;
541                 table_nr++;
542         }
543         if (table_nr == 0)
544                 return;
545
546         acpi_tables_addr =
547                 memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
548                                        all_tables_size, PAGE_SIZE);
549         if (!acpi_tables_addr) {
550                 WARN_ON(1);
551                 return;
552         }
553         /*
554          * Only calling e820_add_reserve does not work and the
555          * tables are invalid (memory got used) later.
556          * memblock_reserve works as expected and the tables won't get modified.
557          * But it's not enough on X86 because ioremap will
558          * complain later (used by acpi_os_map_memory) that the pages
559          * that should get mapped are not marked "reserved".
560          * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
561          * works fine.
562          */
563         memblock_reserve(acpi_tables_addr, all_tables_size);
564         arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
565
566         /*
567          * early_ioremap only can remap 256k one time. If we map all
568          * tables one time, we will hit the limit. Need to map chunks
569          * one by one during copying the same as that in relocate_initrd().
570          */
571         for (no = 0; no < table_nr; no++) {
572                 unsigned char *src_p = acpi_initrd_files[no].data;
573                 phys_addr_t size = acpi_initrd_files[no].size;
574                 phys_addr_t dest_addr = acpi_tables_addr + total_offset;
575                 phys_addr_t slop, clen;
576                 char *dest_p;
577
578                 total_offset += size;
579
580                 while (size) {
581                         slop = dest_addr & ~PAGE_MASK;
582                         clen = size;
583                         if (clen > MAP_CHUNK_SIZE - slop)
584                                 clen = MAP_CHUNK_SIZE - slop;
585                         dest_p = early_memremap(dest_addr & PAGE_MASK,
586                                                 clen + slop);
587                         memcpy(dest_p + slop, src_p, clen);
588                         early_memunmap(dest_p, clen + slop);
589                         src_p += clen;
590                         dest_addr += clen;
591                         size -= clen;
592                 }
593         }
594 }
595
596 static acpi_status
597 acpi_table_initrd_override(struct acpi_table_header *existing_table,
598                            acpi_physical_address *address, u32 *length)
599 {
600         int table_offset = 0;
601         int table_index = 0;
602         struct acpi_table_header *table;
603         u32 table_length;
604
605         *length = 0;
606         *address = 0;
607         if (!acpi_tables_addr)
608                 return AE_OK;
609
610         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
611                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
612                                            ACPI_HEADER_SIZE);
613                 if (table_offset + table->length > all_tables_size) {
614                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
615                         WARN_ON(1);
616                         return AE_OK;
617                 }
618
619                 table_length = table->length;
620
621                 /* Only override tables matched */
622                 if (memcmp(existing_table->signature, table->signature, 4) ||
623                     memcmp(table->oem_id, existing_table->oem_id,
624                            ACPI_OEM_ID_SIZE) ||
625                     memcmp(table->oem_table_id, existing_table->oem_table_id,
626                            ACPI_OEM_TABLE_ID_SIZE)) {
627                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
628                         goto next_table;
629                 }
630                 /*
631                  * Mark the table to avoid being used in
632                  * acpi_table_initrd_scan() and check the revision.
633                  */
634                 if (test_and_set_bit(table_index, acpi_initrd_installed) ||
635                     existing_table->oem_revision >= table->oem_revision) {
636                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
637                         goto next_table;
638                 }
639
640                 *length = table_length;
641                 *address = acpi_tables_addr + table_offset;
642                 pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
643                         table->signature, table->oem_id,
644                         table->oem_table_id);
645                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
646                 break;
647
648 next_table:
649                 table_offset += table_length;
650                 table_index++;
651         }
652         return AE_OK;
653 }
654
655 static void __init acpi_table_initrd_scan(void)
656 {
657         int table_offset = 0;
658         int table_index = 0;
659         u32 table_length;
660         struct acpi_table_header *table;
661
662         if (!acpi_tables_addr)
663                 return;
664
665         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
666                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
667                                            ACPI_HEADER_SIZE);
668                 if (table_offset + table->length > all_tables_size) {
669                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
670                         WARN_ON(1);
671                         return;
672                 }
673
674                 table_length = table->length;
675
676                 /* Skip RSDT/XSDT which should only be used for override */
677                 if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
678                     ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
679                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
680                         goto next_table;
681                 }
682                 /*
683                  * Mark the table to avoid being used in
684                  * acpi_table_initrd_override(). Though this is not possible
685                  * because override is disabled in acpi_install_table().
686                  */
687                 if (test_and_set_bit(table_index, acpi_initrd_installed)) {
688                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
689                         goto next_table;
690                 }
691
692                 pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
693                         table->signature, table->oem_id,
694                         table->oem_table_id);
695                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
696                 acpi_install_table(acpi_tables_addr + table_offset, TRUE);
697 next_table:
698                 table_offset += table_length;
699                 table_index++;
700         }
701 }
702 #else
703 static acpi_status
704 acpi_table_initrd_override(struct acpi_table_header *existing_table,
705                            acpi_physical_address *address,
706                            u32 *table_length)
707 {
708         *table_length = 0;
709         *address = 0;
710         return AE_OK;
711 }
712
713 static void __init acpi_table_initrd_scan(void)
714 {
715 }
716 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
717
718 acpi_status
719 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
720                                 acpi_physical_address *address,
721                                 u32 *table_length)
722 {
723         return acpi_table_initrd_override(existing_table, address,
724                                           table_length);
725 }
726
727 acpi_status
728 acpi_os_table_override(struct acpi_table_header *existing_table,
729                        struct acpi_table_header **new_table)
730 {
731         if (!existing_table || !new_table)
732                 return AE_BAD_PARAMETER;
733
734         *new_table = NULL;
735
736 #ifdef CONFIG_ACPI_CUSTOM_DSDT
737         if (strncmp(existing_table->signature, "DSDT", 4) == 0)
738                 *new_table = (struct acpi_table_header *)AmlCode;
739 #endif
740         if (*new_table != NULL)
741                 acpi_table_taint(existing_table);
742         return AE_OK;
743 }
744
745 /*
746  * acpi_table_init()
747  *
748  * find RSDP, find and checksum SDT/XSDT.
749  * checksum all tables, print SDT/XSDT
750  *
751  * result: sdt_entry[] is initialized
752  */
753
754 int __init acpi_table_init(void)
755 {
756         acpi_status status;
757
758         if (acpi_verify_table_checksum) {
759                 pr_info("Early table checksum verification enabled\n");
760                 acpi_gbl_verify_table_checksum = TRUE;
761         } else {
762                 pr_info("Early table checksum verification disabled\n");
763                 acpi_gbl_verify_table_checksum = FALSE;
764         }
765
766         status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
767         if (ACPI_FAILURE(status))
768                 return -EINVAL;
769         acpi_table_initrd_scan();
770
771         check_multiple_madt();
772         return 0;
773 }
774
775 static int __init acpi_parse_apic_instance(char *str)
776 {
777         if (!str)
778                 return -EINVAL;
779
780         if (kstrtoint(str, 0, &acpi_apic_instance))
781                 return -EINVAL;
782
783         pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
784
785         return 0;
786 }
787
788 early_param("acpi_apic_instance", acpi_parse_apic_instance);
789
790 static int __init acpi_force_table_verification_setup(char *s)
791 {
792         acpi_verify_table_checksum = true;
793
794         return 0;
795 }
796
797 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
798
799 static int __init acpi_force_32bit_fadt_addr(char *s)
800 {
801         pr_info("Forcing 32 Bit FADT addresses\n");
802         acpi_gbl_use32_bit_fadt_addresses = TRUE;
803
804         return 0;
805 }
806
807 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);