Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[sfrench/cifs-2.6.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/memblock.h>
35 #include <linux/earlycpio.h>
36 #include <linux/initrd.h>
37 #include "internal.h"
38
39 #ifdef CONFIG_ACPI_CUSTOM_DSDT
40 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
41 #endif
42
43 #define ACPI_MAX_TABLES         128
44
45 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
46 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
47
48 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
49
50 static int acpi_apic_instance __initdata;
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 = 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[%p])\n",
155                                 (void *)(unsigned long)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         default:
214                 pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
215                         header->type);
216                 break;
217         }
218 }
219
220 /**
221  * acpi_parse_entries_array - for each proc_num find a suitable subtable
222  *
223  * @id: table id (for debugging purposes)
224  * @table_size: size of the root table
225  * @table_header: where does the table start?
226  * @proc: array of acpi_subtable_proc struct containing entry id
227  *        and associated handler with it
228  * @proc_num: how big proc is?
229  * @max_entries: how many entries can we process?
230  *
231  * For each proc_num find a subtable with proc->id and run proc->handler
232  * on it. Assumption is that there's only single handler for particular
233  * entry id.
234  *
235  * The table_size is not the size of the complete ACPI table (the length
236  * field in the header struct), but only the size of the root table; i.e.,
237  * the offset from the very first byte of the complete ACPI table, to the
238  * first byte of the very first subtable.
239  *
240  * On success returns sum of all matching entries for all proc handlers.
241  * Otherwise, -ENODEV or -EINVAL is returned.
242  */
243 static int __init
244 acpi_parse_entries_array(char *id, unsigned long table_size,
245                 struct acpi_table_header *table_header,
246                 struct acpi_subtable_proc *proc, int proc_num,
247                 unsigned int max_entries)
248 {
249         struct acpi_subtable_header *entry;
250         unsigned long table_end;
251         int count = 0;
252         int errs = 0;
253         int i;
254
255         if (acpi_disabled)
256                 return -ENODEV;
257
258         if (!id)
259                 return -EINVAL;
260
261         if (!table_size)
262                 return -EINVAL;
263
264         if (!table_header) {
265                 pr_warn("%4.4s not present\n", id);
266                 return -ENODEV;
267         }
268
269         table_end = (unsigned long)table_header + table_header->length;
270
271         /* Parse all entries looking for a match. */
272
273         entry = (struct acpi_subtable_header *)
274             ((unsigned long)table_header + table_size);
275
276         while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
277                table_end) {
278                 if (max_entries && count >= max_entries)
279                         break;
280
281                 for (i = 0; i < proc_num; i++) {
282                         if (entry->type != proc[i].id)
283                                 continue;
284                         if (!proc[i].handler ||
285                              (!errs && proc[i].handler(entry, table_end))) {
286                                 errs++;
287                                 continue;
288                         }
289
290                         proc[i].count++;
291                         break;
292                 }
293                 if (i != proc_num)
294                         count++;
295
296                 /*
297                  * If entry->length is 0, break from this loop to avoid
298                  * infinite loop.
299                  */
300                 if (entry->length == 0) {
301                         pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
302                         return -EINVAL;
303                 }
304
305                 entry = (struct acpi_subtable_header *)
306                     ((unsigned long)entry + entry->length);
307         }
308
309         if (max_entries && count > max_entries) {
310                 pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
311                         id, proc->id, count);
312         }
313
314         return errs ? -EINVAL : count;
315 }
316
317 int __init
318 acpi_table_parse_entries_array(char *id,
319                          unsigned long table_size,
320                          struct acpi_subtable_proc *proc, int proc_num,
321                          unsigned int max_entries)
322 {
323         struct acpi_table_header *table_header = NULL;
324         int count;
325         u32 instance = 0;
326
327         if (acpi_disabled)
328                 return -ENODEV;
329
330         if (!id)
331                 return -EINVAL;
332
333         if (!strncmp(id, ACPI_SIG_MADT, 4))
334                 instance = acpi_apic_instance;
335
336         acpi_get_table(id, instance, &table_header);
337         if (!table_header) {
338                 pr_warn("%4.4s not present\n", id);
339                 return -ENODEV;
340         }
341
342         count = acpi_parse_entries_array(id, table_size, table_header,
343                         proc, proc_num, max_entries);
344
345         acpi_put_table(table_header);
346         return count;
347 }
348
349 int __init
350 acpi_table_parse_entries(char *id,
351                         unsigned long table_size,
352                         int entry_id,
353                         acpi_tbl_entry_handler handler,
354                         unsigned int max_entries)
355 {
356         struct acpi_subtable_proc proc = {
357                 .id             = entry_id,
358                 .handler        = handler,
359         };
360
361         return acpi_table_parse_entries_array(id, table_size, &proc, 1,
362                                                 max_entries);
363 }
364
365 int __init
366 acpi_table_parse_madt(enum acpi_madt_type id,
367                       acpi_tbl_entry_handler handler, unsigned int max_entries)
368 {
369         return acpi_table_parse_entries(ACPI_SIG_MADT,
370                                             sizeof(struct acpi_table_madt), id,
371                                             handler, max_entries);
372 }
373
374 /**
375  * acpi_table_parse - find table with @id, run @handler on it
376  * @id: table id to find
377  * @handler: handler to run
378  *
379  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
380  * run @handler on it.
381  *
382  * Return 0 if table found, -errno if not.
383  */
384 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
385 {
386         struct acpi_table_header *table = NULL;
387
388         if (acpi_disabled)
389                 return -ENODEV;
390
391         if (!id || !handler)
392                 return -EINVAL;
393
394         if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
395                 acpi_get_table(id, acpi_apic_instance, &table);
396         else
397                 acpi_get_table(id, 0, &table);
398
399         if (table) {
400                 handler(table);
401                 acpi_put_table(table);
402                 return 0;
403         } else
404                 return -ENODEV;
405 }
406
407 /*
408  * The BIOS is supposed to supply a single APIC/MADT,
409  * but some report two.  Provide a knob to use either.
410  * (don't you wish instance 0 and 1 were not the same?)
411  */
412 static void __init check_multiple_madt(void)
413 {
414         struct acpi_table_header *table = NULL;
415
416         acpi_get_table(ACPI_SIG_MADT, 2, &table);
417         if (table) {
418                 pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
419                         acpi_apic_instance);
420                 pr_warn("If \"acpi_apic_instance=%d\" works better, "
421                         "notify linux-acpi@vger.kernel.org\n",
422                         acpi_apic_instance ? 0 : 2);
423                 acpi_put_table(table);
424
425         } else
426                 acpi_apic_instance = 0;
427
428         return;
429 }
430
431 static void acpi_table_taint(struct acpi_table_header *table)
432 {
433         pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
434                 table->signature, table->oem_table_id);
435         add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
436 }
437
438 #ifdef CONFIG_ACPI_TABLE_UPGRADE
439 static u64 acpi_tables_addr;
440 static int all_tables_size;
441
442 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
443 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
444 {
445         u8 sum = 0;
446         u8 *end = buffer + length;
447
448         while (buffer < end)
449                 sum = (u8) (sum + *(buffer++));
450         return sum;
451 }
452
453 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
454 static const char * const table_sigs[] = {
455         ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
456         ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
457         ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
458         ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
459         ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
460         ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
461         ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
462         ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
463         ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, ACPI_SIG_IORT,
464         ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, NULL };
465
466 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
467
468 #define NR_ACPI_INITRD_TABLES 64
469 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
470 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
471
472 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
473
474 void __init acpi_table_upgrade(void)
475 {
476         void *data;
477         size_t size;
478         int sig, no, table_nr = 0, total_offset = 0;
479         long offset = 0;
480         struct acpi_table_header *table;
481         char cpio_path[32] = "kernel/firmware/acpi/";
482         struct cpio_data file;
483
484         if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
485                 data = __initramfs_start;
486                 size = __initramfs_size;
487         } else {
488                 data = (void *)initrd_start;
489                 size = initrd_end - initrd_start;
490         }
491
492         if (data == NULL || size == 0)
493                 return;
494
495         for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
496                 file = find_cpio_data(cpio_path, data, size, &offset);
497                 if (!file.data)
498                         break;
499
500                 data += offset;
501                 size -= offset;
502
503                 if (file.size < sizeof(struct acpi_table_header)) {
504                         pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
505                                 cpio_path, file.name);
506                         continue;
507                 }
508
509                 table = file.data;
510
511                 for (sig = 0; table_sigs[sig]; sig++)
512                         if (!memcmp(table->signature, table_sigs[sig], 4))
513                                 break;
514
515                 if (!table_sigs[sig]) {
516                         pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
517                                 cpio_path, file.name);
518                         continue;
519                 }
520                 if (file.size != table->length) {
521                         pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
522                                 cpio_path, file.name);
523                         continue;
524                 }
525                 if (acpi_table_checksum(file.data, table->length)) {
526                         pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
527                                 cpio_path, file.name);
528                         continue;
529                 }
530
531                 pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
532                         table->signature, cpio_path, file.name, table->length);
533
534                 all_tables_size += table->length;
535                 acpi_initrd_files[table_nr].data = file.data;
536                 acpi_initrd_files[table_nr].size = file.size;
537                 table_nr++;
538         }
539         if (table_nr == 0)
540                 return;
541
542         acpi_tables_addr =
543                 memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
544                                        all_tables_size, PAGE_SIZE);
545         if (!acpi_tables_addr) {
546                 WARN_ON(1);
547                 return;
548         }
549         /*
550          * Only calling e820_add_reserve does not work and the
551          * tables are invalid (memory got used) later.
552          * memblock_reserve works as expected and the tables won't get modified.
553          * But it's not enough on X86 because ioremap will
554          * complain later (used by acpi_os_map_memory) that the pages
555          * that should get mapped are not marked "reserved".
556          * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
557          * works fine.
558          */
559         memblock_reserve(acpi_tables_addr, all_tables_size);
560         arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
561
562         /*
563          * early_ioremap only can remap 256k one time. If we map all
564          * tables one time, we will hit the limit. Need to map chunks
565          * one by one during copying the same as that in relocate_initrd().
566          */
567         for (no = 0; no < table_nr; no++) {
568                 unsigned char *src_p = acpi_initrd_files[no].data;
569                 phys_addr_t size = acpi_initrd_files[no].size;
570                 phys_addr_t dest_addr = acpi_tables_addr + total_offset;
571                 phys_addr_t slop, clen;
572                 char *dest_p;
573
574                 total_offset += size;
575
576                 while (size) {
577                         slop = dest_addr & ~PAGE_MASK;
578                         clen = size;
579                         if (clen > MAP_CHUNK_SIZE - slop)
580                                 clen = MAP_CHUNK_SIZE - slop;
581                         dest_p = early_memremap(dest_addr & PAGE_MASK,
582                                                 clen + slop);
583                         memcpy(dest_p + slop, src_p, clen);
584                         early_memunmap(dest_p, clen + slop);
585                         src_p += clen;
586                         dest_addr += clen;
587                         size -= clen;
588                 }
589         }
590 }
591
592 static acpi_status
593 acpi_table_initrd_override(struct acpi_table_header *existing_table,
594                            acpi_physical_address *address, u32 *length)
595 {
596         int table_offset = 0;
597         int table_index = 0;
598         struct acpi_table_header *table;
599         u32 table_length;
600
601         *length = 0;
602         *address = 0;
603         if (!acpi_tables_addr)
604                 return AE_OK;
605
606         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
607                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
608                                            ACPI_HEADER_SIZE);
609                 if (table_offset + table->length > all_tables_size) {
610                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
611                         WARN_ON(1);
612                         return AE_OK;
613                 }
614
615                 table_length = table->length;
616
617                 /* Only override tables matched */
618                 if (memcmp(existing_table->signature, table->signature, 4) ||
619                     memcmp(table->oem_id, existing_table->oem_id,
620                            ACPI_OEM_ID_SIZE) ||
621                     memcmp(table->oem_table_id, existing_table->oem_table_id,
622                            ACPI_OEM_TABLE_ID_SIZE)) {
623                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
624                         goto next_table;
625                 }
626                 /*
627                  * Mark the table to avoid being used in
628                  * acpi_table_initrd_scan() and check the revision.
629                  */
630                 if (test_and_set_bit(table_index, acpi_initrd_installed) ||
631                     existing_table->oem_revision >= table->oem_revision) {
632                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
633                         goto next_table;
634                 }
635
636                 *length = table_length;
637                 *address = acpi_tables_addr + table_offset;
638                 pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
639                         table->signature, table->oem_id,
640                         table->oem_table_id);
641                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
642                 break;
643
644 next_table:
645                 table_offset += table_length;
646                 table_index++;
647         }
648         return AE_OK;
649 }
650
651 static void __init acpi_table_initrd_scan(void)
652 {
653         int table_offset = 0;
654         int table_index = 0;
655         u32 table_length;
656         struct acpi_table_header *table;
657
658         if (!acpi_tables_addr)
659                 return;
660
661         while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
662                 table = acpi_os_map_memory(acpi_tables_addr + table_offset,
663                                            ACPI_HEADER_SIZE);
664                 if (table_offset + table->length > all_tables_size) {
665                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
666                         WARN_ON(1);
667                         return;
668                 }
669
670                 table_length = table->length;
671
672                 /* Skip RSDT/XSDT which should only be used for override */
673                 if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
674                     ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
675                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
676                         goto next_table;
677                 }
678                 /*
679                  * Mark the table to avoid being used in
680                  * acpi_table_initrd_override(). Though this is not possible
681                  * because override is disabled in acpi_install_table().
682                  */
683                 if (test_and_set_bit(table_index, acpi_initrd_installed)) {
684                         acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
685                         goto next_table;
686                 }
687
688                 pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
689                         table->signature, table->oem_id,
690                         table->oem_table_id);
691                 acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
692                 acpi_install_table(acpi_tables_addr + table_offset, TRUE);
693 next_table:
694                 table_offset += table_length;
695                 table_index++;
696         }
697 }
698 #else
699 static acpi_status
700 acpi_table_initrd_override(struct acpi_table_header *existing_table,
701                            acpi_physical_address *address,
702                            u32 *table_length)
703 {
704         *table_length = 0;
705         *address = 0;
706         return AE_OK;
707 }
708
709 static void __init acpi_table_initrd_scan(void)
710 {
711 }
712 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
713
714 acpi_status
715 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
716                                 acpi_physical_address *address,
717                                 u32 *table_length)
718 {
719         return acpi_table_initrd_override(existing_table, address,
720                                           table_length);
721 }
722
723 #ifdef CONFIG_ACPI_CUSTOM_DSDT
724 static void *amlcode __attribute__ ((weakref("AmlCode")));
725 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
726 #endif
727
728 acpi_status
729 acpi_os_table_override(struct acpi_table_header *existing_table,
730                        struct acpi_table_header **new_table)
731 {
732         if (!existing_table || !new_table)
733                 return AE_BAD_PARAMETER;
734
735         *new_table = NULL;
736
737 #ifdef CONFIG_ACPI_CUSTOM_DSDT
738         if (!strncmp(existing_table->signature, "DSDT", 4)) {
739                 *new_table = (struct acpi_table_header *)&amlcode;
740                 if (!(*new_table))
741                         *new_table = (struct acpi_table_header *)&dsdt_amlcode;
742         }
743 #endif
744         if (*new_table != NULL)
745                 acpi_table_taint(existing_table);
746         return AE_OK;
747 }
748
749 /*
750  * acpi_table_init()
751  *
752  * find RSDP, find and checksum SDT/XSDT.
753  * checksum all tables, print SDT/XSDT
754  *
755  * result: sdt_entry[] is initialized
756  */
757
758 int __init acpi_table_init(void)
759 {
760         acpi_status status;
761
762         if (acpi_verify_table_checksum) {
763                 pr_info("Early table checksum verification enabled\n");
764                 acpi_gbl_enable_table_validation = TRUE;
765         } else {
766                 pr_info("Early table checksum verification disabled\n");
767                 acpi_gbl_enable_table_validation = FALSE;
768         }
769
770         status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
771         if (ACPI_FAILURE(status))
772                 return -EINVAL;
773         acpi_table_initrd_scan();
774
775         check_multiple_madt();
776         return 0;
777 }
778
779 static int __init acpi_parse_apic_instance(char *str)
780 {
781         if (!str)
782                 return -EINVAL;
783
784         if (kstrtoint(str, 0, &acpi_apic_instance))
785                 return -EINVAL;
786
787         pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
788
789         return 0;
790 }
791
792 early_param("acpi_apic_instance", acpi_parse_apic_instance);
793
794 static int __init acpi_force_table_verification_setup(char *s)
795 {
796         acpi_verify_table_checksum = true;
797
798         return 0;
799 }
800
801 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
802
803 static int __init acpi_force_32bit_fadt_addr(char *s)
804 {
805         pr_info("Forcing 32 Bit FADT addresses\n");
806         acpi_gbl_use32_bit_fadt_addresses = TRUE;
807
808         return 0;
809 }
810
811 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);