Merge remote-tracking branches 'asoc/topic/atmel', 'asoc/topic/chmap', 'asoc/topic...
[linux-2.6-block.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 "internal.h"
39
40 #ifdef CONFIG_ACPI_CUSTOM_DSDT
41 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
42 #endif
43
44 #define ACPI_MAX_TABLES         128
45
46 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
47 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
48
49 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
50
51 static int acpi_apic_instance __initdata;
52
53 /*
54  * Disable table checksum verification for the early stage due to the size
55  * limitation of the current x86 early mapping implementation.
56  */
57 static bool acpi_verify_table_checksum __initdata = false;
58
59 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
60 {
61         if (!header)
62                 return;
63
64         switch (header->type) {
65
66         case ACPI_MADT_TYPE_LOCAL_APIC:
67                 {
68                         struct acpi_madt_local_apic *p =
69                             (struct acpi_madt_local_apic *)header;
70                         pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
71                                  p->processor_id, p->id,
72                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
73                 }
74                 break;
75
76         case ACPI_MADT_TYPE_LOCAL_X2APIC:
77                 {
78                         struct acpi_madt_local_x2apic *p =
79                             (struct acpi_madt_local_x2apic *)header;
80                         pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
81                                  p->local_apic_id, p->uid,
82                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
83                 }
84                 break;
85
86         case ACPI_MADT_TYPE_IO_APIC:
87                 {
88                         struct acpi_madt_io_apic *p =
89                             (struct acpi_madt_io_apic *)header;
90                         pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
91                                  p->id, p->address, p->global_irq_base);
92                 }
93                 break;
94
95         case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
96                 {
97                         struct acpi_madt_interrupt_override *p =
98                             (struct acpi_madt_interrupt_override *)header;
99                         pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
100                                 p->bus, p->source_irq, p->global_irq,
101                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
102                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
103                         if (p->inti_flags  &
104                             ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
105                                 pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
106                                         p->inti_flags  &
107                                         ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
108                 }
109                 break;
110
111         case ACPI_MADT_TYPE_NMI_SOURCE:
112                 {
113                         struct acpi_madt_nmi_source *p =
114                             (struct acpi_madt_nmi_source *)header;
115                         pr_info("NMI_SRC (%s %s global_irq %d)\n",
116                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
117                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
118                                 p->global_irq);
119                 }
120                 break;
121
122         case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
123                 {
124                         struct acpi_madt_local_apic_nmi *p =
125                             (struct acpi_madt_local_apic_nmi *)header;
126                         pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
127                                 p->processor_id,
128                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK ],
129                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
130                                 p->lint);
131                 }
132                 break;
133
134         case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
135                 {
136                         u16 polarity, trigger;
137                         struct acpi_madt_local_x2apic_nmi *p =
138                             (struct acpi_madt_local_x2apic_nmi *)header;
139
140                         polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
141                         trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
142
143                         pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
144                                 p->uid,
145                                 mps_inti_flags_polarity[polarity],
146                                 mps_inti_flags_trigger[trigger],
147                                 p->lint);
148                 }
149                 break;
150
151         case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
152                 {
153                         struct acpi_madt_local_apic_override *p =
154                             (struct acpi_madt_local_apic_override *)header;
155                         pr_info("LAPIC_ADDR_OVR (address[%p])\n",
156                                 (void *)(unsigned long)p->address);
157                 }
158                 break;
159
160         case ACPI_MADT_TYPE_IO_SAPIC:
161                 {
162                         struct acpi_madt_io_sapic *p =
163                             (struct acpi_madt_io_sapic *)header;
164                         pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
165                                  p->id, (void *)(unsigned long)p->address,
166                                  p->global_irq_base);
167                 }
168                 break;
169
170         case ACPI_MADT_TYPE_LOCAL_SAPIC:
171                 {
172                         struct acpi_madt_local_sapic *p =
173                             (struct acpi_madt_local_sapic *)header;
174                         pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
175                                  p->processor_id, p->id, p->eid,
176                                  (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
177                 }
178                 break;
179
180         case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
181                 {
182                         struct acpi_madt_interrupt_source *p =
183                             (struct acpi_madt_interrupt_source *)header;
184                         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",
185                                 mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
186                                 mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
187                                 p->type, p->id, p->eid, p->io_sapic_vector,
188                                 p->global_irq);
189                 }
190                 break;
191
192         case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
193                 {
194                         struct acpi_madt_generic_interrupt *p =
195                                 (struct acpi_madt_generic_interrupt *)header;
196                         pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
197                                  p->uid, p->base_address,
198                                  p->arm_mpidr,
199                                  (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
200
201                 }
202                 break;
203
204         case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
205                 {
206                         struct acpi_madt_generic_distributor *p =
207                                 (struct acpi_madt_generic_distributor *)header;
208                         pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
209                                  p->gic_id, p->base_address,
210                                  p->global_irq_base);
211                 }
212                 break;
213
214         default:
215                 pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
216                         header->type);
217                 break;
218         }
219 }
220
221 /**
222  * acpi_parse_entries_array - for each proc_num find a suitable subtable
223  *
224  * @id: table id (for debugging purposes)
225  * @table_size: single entry size
226  * @table_header: where does the table start?
227  * @proc: array of acpi_subtable_proc struct containing entry id
228  *        and associated handler with it
229  * @proc_num: how big proc is?
230  * @max_entries: how many entries can we process?
231  *
232  * For each proc_num find a subtable with proc->id and run proc->handler
233  * on it. Assumption is that there's only single handler for particular
234  * entry id.
235  *
236  * On success returns sum of all matching entries for all proc handlers.
237  * Otherwise, -ENODEV or -EINVAL is returned.
238  */
239 static int __init
240 acpi_parse_entries_array(char *id, unsigned long table_size,
241                 struct acpi_table_header *table_header,
242                 struct acpi_subtable_proc *proc, int proc_num,
243                 unsigned int max_entries)
244 {
245         struct acpi_subtable_header *entry;
246         unsigned long table_end;
247         int count = 0;
248         int errs = 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                              (!errs && proc[i].handler(entry, table_end))) {
282                                 errs++;
283                                 continue;
284                         }
285
286                         proc[i].count++;
287                         break;
288                 }
289                 if (i != proc_num)
290                         count++;
291
292                 /*
293                  * If entry->length is 0, break from this loop to avoid
294                  * infinite loop.
295                  */
296                 if (entry->length == 0) {
297                         pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
298                         return -EINVAL;
299                 }
300
301                 entry = (struct acpi_subtable_header *)
302                     ((unsigned long)entry + entry->length);
303         }
304
305         if (max_entries && count > max_entries) {
306                 pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
307                         id, proc->id, count);
308         }
309
310         return errs ? -EINVAL : count;
311 }
312
313 int __init
314 acpi_parse_entries(char *id,
315                         unsigned long table_size,
316                         acpi_tbl_entry_handler handler,
317                         struct acpi_table_header *table_header,
318                         int entry_id, unsigned int max_entries)
319 {
320         struct acpi_subtable_proc proc = {
321                 .id             = entry_id,
322                 .handler        = handler,
323         };
324
325         return acpi_parse_entries_array(id, table_size, table_header,
326                         &proc, 1, max_entries);
327 }
328
329 int __init
330 acpi_table_parse_entries_array(char *id,
331                          unsigned long table_size,
332                          struct acpi_subtable_proc *proc, int proc_num,
333                          unsigned int max_entries)
334 {
335         struct acpi_table_header *table_header = NULL;
336         int count;
337         u32 instance = 0;
338
339         if (acpi_disabled)
340                 return -ENODEV;
341
342         if (!id)
343                 return -EINVAL;
344
345         if (!strncmp(id, ACPI_SIG_MADT, 4))
346                 instance = acpi_apic_instance;
347
348         acpi_get_table(id, instance, &table_header);
349         if (!table_header) {
350                 pr_warn("%4.4s not present\n", id);
351                 return -ENODEV;
352         }
353
354         count = acpi_parse_entries_array(id, table_size, table_header,
355                         proc, proc_num, max_entries);
356
357         acpi_put_table(table_header);
358         return count;
359 }
360
361 int __init
362 acpi_table_parse_entries(char *id,
363                         unsigned long table_size,
364                         int entry_id,
365                         acpi_tbl_entry_handler handler,
366                         unsigned int max_entries)
367 {
368         struct acpi_subtable_proc proc = {
369                 .id             = entry_id,
370                 .handler        = handler,
371         };
372
373         return acpi_table_parse_entries_array(id, table_size, &proc, 1,
374                                                 max_entries);
375 }
376
377 int __init
378 acpi_table_parse_madt(enum acpi_madt_type id,
379                       acpi_tbl_entry_handler handler, unsigned int max_entries)
380 {
381         return acpi_table_parse_entries(ACPI_SIG_MADT,
382                                             sizeof(struct acpi_table_madt), id,
383                                             handler, max_entries);
384 }
385
386 /**
387  * acpi_table_parse - find table with @id, run @handler on it
388  * @id: table id to find
389  * @handler: handler to run
390  *
391  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
392  * run @handler on it.
393  *
394  * Return 0 if table found, -errno if not.
395  */
396 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
397 {
398         struct acpi_table_header *table = NULL;
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(id, acpi_apic_instance, &table);
408         else
409                 acpi_get_table(id, 0, &table);
410
411         if (table) {
412                 handler(table);
413                 acpi_put_table(table);
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
428         acpi_get_table(ACPI_SIG_MADT, 2, &table);
429         if (table) {
430                 pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
431                         acpi_apic_instance);
432                 pr_warn("If \"acpi_apic_instance=%d\" works better, "
433                         "notify linux-acpi@vger.kernel.org\n",
434                         acpi_apic_instance ? 0 : 2);
435                 acpi_put_table(table);
436
437         } else
438                 acpi_apic_instance = 0;
439
440         return;
441 }
442
443 static void acpi_table_taint(struct acpi_table_header *table)
444 {
445         pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
446                 table->signature, table->oem_table_id);
447         add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
448 }
449
450 #ifdef CONFIG_ACPI_TABLE_UPGRADE
451 static u64 acpi_tables_addr;
452 static int all_tables_size;
453
454 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
455 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
456 {
457         u8 sum = 0;
458         u8 *end = buffer + length;
459
460         while (buffer < end)
461                 sum = (u8) (sum + *(buffer++));
462         return sum;
463 }
464
465 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
466 static const char * const table_sigs[] = {
467         ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
468         ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
469         ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
470         ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
471         ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
472         ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
473         ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
474         ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
475         ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
476
477 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
478
479 #define NR_ACPI_INITRD_TABLES 64
480 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
481 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
482
483 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
484
485 void __init acpi_table_upgrade(void)
486 {
487         void *data = (void *)initrd_start;
488         size_t size = initrd_end - initrd_start;
489         int sig, no, table_nr = 0, total_offset = 0;
490         long offset = 0;
491         struct acpi_table_header *table;
492         char cpio_path[32] = "kernel/firmware/acpi/";
493         struct cpio_data file;
494
495         if (data == NULL || size == 0)
496                 return;
497
498         for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
499                 file = find_cpio_data(cpio_path, data, size, &offset);
500                 if (!file.data)
501                         break;
502
503                 data += offset;
504                 size -= offset;
505
506                 if (file.size < sizeof(struct acpi_table_header)) {
507                         pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
508                                 cpio_path, file.name);
509                         continue;
510                 }
511
512                 table = file.data;
513
514                 for (sig = 0; table_sigs[sig]; sig++)
515                         if (!memcmp(table->signature, table_sigs[sig], 4))
516                                 break;
517
518                 if (!table_sigs[sig]) {
519                         pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
520                                 cpio_path, file.name);
521                         continue;
522                 }
523                 if (file.size != table->length) {
524                         pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
525                                 cpio_path, file.name);
526                         continue;
527                 }
528                 if (acpi_table_checksum(file.data, table->length)) {
529                         pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
530                                 cpio_path, file.name);
531                         continue;
532                 }
533
534                 pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
535                         table->signature, cpio_path, file.name, table->length);
536
537                 all_tables_size += table->length;
538                 acpi_initrd_files[table_nr].data = file.data;
539                 acpi_initrd_files[table_nr].size = file.size;
540                 table_nr++;
541         }
542         if (table_nr == 0)
543                 return;
544
545         acpi_tables_addr =
546                 memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
547                                        all_tables_size, PAGE_SIZE);
548         if (!acpi_tables_addr) {
549                 WARN_ON(1);
550                 return;
551         }
552         /*
553          * Only calling e820_add_reserve does not work and the
554          * tables are invalid (memory got used) later.
555          * memblock_reserve works as expected and the tables won't get modified.
556          * But it's not enough on X86 because ioremap will
557          * complain later (used by acpi_os_map_memory) that the pages
558          * that should get mapped are not marked "reserved".
559          * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
560          * works fine.
561          */
562         memblock_reserve(acpi_tables_addr, all_tables_size);
563         arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
564
565         /*
566          * early_ioremap only can remap 256k one time. If we map all
567          * tables one time, we will hit the limit. Need to map chunks
568          * one by one during copying the same as that in relocate_initrd().
569          */
570         for (no = 0; no < table_nr; no++) {
571                 unsigned char *src_p = acpi_initrd_files[no].data;
572                 phys_addr_t size = acpi_initrd_files[no].size;
573                 phys_addr_t dest_addr = acpi_tables_addr + total_offset;
574                 phys_addr_t slop, clen;
575                 char *dest_p;
576
577                 total_offset += size;
578
579                 while (size) {
580                         slop = dest_addr & ~PAGE_MASK;
581                         clen = size;
582                         if (clen > MAP_CHUNK_SIZE - slop)
583                                 clen = MAP_CHUNK_SIZE - slop;
584                         dest_p = early_memremap(dest_addr & PAGE_MASK,
585                                                 clen + slop);
586                         memcpy(dest_p + slop, src_p, clen);
587                         early_memunmap(dest_p, clen + slop);
588                         src_p += clen;
589                         dest_addr += clen;
590                         size -= clen;
591                 }
592         }
593 }
594
595 static acpi_status
596 acpi_table_initrd_override(struct acpi_table_header *existing_table,
597                            acpi_physical_address *address, u32 *length)
598 {
599         int table_offset = 0;
600         int table_index = 0;
601         struct acpi_table_header *table;
602         u32 table_length;
603
604         *length = 0;
605         *address = 0;
606         if (!acpi_tables_addr)
607                 return AE_OK;
608
609         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
610                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
611                                            ACPI_HEADER_SIZE);
612                 if (table_offset + table->length > all_tables_size) {
613                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
614                         WARN_ON(1);
615                         return AE_OK;
616                 }
617
618                 table_length = table->length;
619
620                 /* Only override tables matched */
621                 if (memcmp(existing_table->signature, table->signature, 4) ||
622                     memcmp(table->oem_id, existing_table->oem_id,
623                            ACPI_OEM_ID_SIZE) ||
624                     memcmp(table->oem_table_id, existing_table->oem_table_id,
625                            ACPI_OEM_TABLE_ID_SIZE)) {
626                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
627                         goto next_table;
628                 }
629                 /*
630                  * Mark the table to avoid being used in
631                  * acpi_table_initrd_scan() and check the revision.
632                  */
633                 if (test_and_set_bit(table_index, acpi_initrd_installed) ||
634                     existing_table->oem_revision >= table->oem_revision) {
635                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
636                         goto next_table;
637                 }
638
639                 *length = table_length;
640                 *address = acpi_tables_addr + table_offset;
641                 pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
642                         table->signature, table->oem_id,
643                         table->oem_table_id);
644                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
645                 break;
646
647 next_table:
648                 table_offset += table_length;
649                 table_index++;
650         }
651         return AE_OK;
652 }
653
654 static void __init acpi_table_initrd_scan(void)
655 {
656         int table_offset = 0;
657         int table_index = 0;
658         u32 table_length;
659         struct acpi_table_header *table;
660
661         if (!acpi_tables_addr)
662                 return;
663
664         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
665                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
666                                            ACPI_HEADER_SIZE);
667                 if (table_offset + table->length > all_tables_size) {
668                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
669                         WARN_ON(1);
670                         return;
671                 }
672
673                 table_length = table->length;
674
675                 /* Skip RSDT/XSDT which should only be used for override */
676                 if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
677                     ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
678                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
679                         goto next_table;
680                 }
681                 /*
682                  * Mark the table to avoid being used in
683                  * acpi_table_initrd_override(). Though this is not possible
684                  * because override is disabled in acpi_install_table().
685                  */
686                 if (test_and_set_bit(table_index, acpi_initrd_installed)) {
687                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
688                         goto next_table;
689                 }
690
691                 pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
692                         table->signature, table->oem_id,
693                         table->oem_table_id);
694                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
695                 acpi_install_table(acpi_tables_addr + table_offset, TRUE);
696 next_table:
697                 table_offset += table_length;
698                 table_index++;
699         }
700 }
701 #else
702 static acpi_status
703 acpi_table_initrd_override(struct acpi_table_header *existing_table,
704                            acpi_physical_address *address,
705                            u32 *table_length)
706 {
707         *table_length = 0;
708         *address = 0;
709         return AE_OK;
710 }
711
712 static void __init acpi_table_initrd_scan(void)
713 {
714 }
715 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
716
717 acpi_status
718 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
719                                 acpi_physical_address *address,
720                                 u32 *table_length)
721 {
722         return acpi_table_initrd_override(existing_table, address,
723                                           table_length);
724 }
725
726 acpi_status
727 acpi_os_table_override(struct acpi_table_header *existing_table,
728                        struct acpi_table_header **new_table)
729 {
730         if (!existing_table || !new_table)
731                 return AE_BAD_PARAMETER;
732
733         *new_table = NULL;
734
735 #ifdef CONFIG_ACPI_CUSTOM_DSDT
736         if (strncmp(existing_table->signature, "DSDT", 4) == 0)
737                 *new_table = (struct acpi_table_header *)AmlCode;
738 #endif
739         if (*new_table != NULL)
740                 acpi_table_taint(existing_table);
741         return AE_OK;
742 }
743
744 /*
745  * acpi_table_init()
746  *
747  * find RSDP, find and checksum SDT/XSDT.
748  * checksum all tables, print SDT/XSDT
749  *
750  * result: sdt_entry[] is initialized
751  */
752
753 int __init acpi_table_init(void)
754 {
755         acpi_status status;
756
757         if (acpi_verify_table_checksum) {
758                 pr_info("Early table checksum verification enabled\n");
759                 acpi_gbl_verify_table_checksum = TRUE;
760         } else {
761                 pr_info("Early table checksum verification disabled\n");
762                 acpi_gbl_verify_table_checksum = FALSE;
763         }
764
765         status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
766         if (ACPI_FAILURE(status))
767                 return -EINVAL;
768         acpi_table_initrd_scan();
769
770         check_multiple_madt();
771         return 0;
772 }
773
774 static int __init acpi_parse_apic_instance(char *str)
775 {
776         if (!str)
777                 return -EINVAL;
778
779         if (kstrtoint(str, 0, &acpi_apic_instance))
780                 return -EINVAL;
781
782         pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
783
784         return 0;
785 }
786
787 early_param("acpi_apic_instance", acpi_parse_apic_instance);
788
789 static int __init acpi_force_table_verification_setup(char *s)
790 {
791         acpi_verify_table_checksum = true;
792
793         return 0;
794 }
795
796 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
797
798 static int __init acpi_force_32bit_fadt_addr(char *s)
799 {
800         pr_info("Forcing 32 Bit FADT addresses\n");
801         acpi_gbl_use32_bit_fadt_addresses = TRUE;
802
803         return 0;
804 }
805
806 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);