1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: tbutils - ACPI Table utilities
5 *
6 * Copyright (C) 2000 - 2025, Intel Corp.
7 *
8 *****************************************************************************/
9
10#include <acpi/acpi.h>
11#include "accommon.h"
12#include "actables.h"
13
14#define _COMPONENT ACPI_TABLES
15ACPI_MODULE_NAME("tbutils")
16
17/* Local prototypes */
18static acpi_physical_address
19acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
20
21/*******************************************************************************
22 *
23 * FUNCTION: acpi_tb_initialize_facs
24 *
25 * PARAMETERS: None
26 *
27 * RETURN: Status
28 *
29 * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
30 * for accessing the Global Lock and Firmware Waking Vector
31 *
32 ******************************************************************************/
33
34acpi_status acpi_tb_initialize_facs(void)
35{
36 struct acpi_table_facs *facs;
37
38 if (acpi_gbl_FADT.Xfacs &&
39 (!acpi_gbl_FADT.facs
40 || !acpi_gbl_use32_bit_facs_addresses)) {
41 (void)acpi_get_table_by_index(table_index: acpi_gbl_xfacs_index,
42 ACPI_CAST_INDIRECT_PTR(struct
43 acpi_table_header,
44 &facs));
45 acpi_gbl_FACS = facs;
46 } else if (acpi_gbl_FADT.facs) {
47 (void)acpi_get_table_by_index(table_index: acpi_gbl_facs_index,
48 ACPI_CAST_INDIRECT_PTR(struct
49 acpi_table_header,
50 &facs));
51 acpi_gbl_FACS = facs;
52 }
53
54 /* If there is no FACS, just continue. There was already an error msg */
55
56 return (AE_OK);
57}
58
59/*******************************************************************************
60 *
61 * FUNCTION: acpi_tb_check_dsdt_header
62 *
63 * PARAMETERS: None
64 *
65 * RETURN: None
66 *
67 * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
68 * if the DSDT has been replaced from outside the OS and/or if
69 * the DSDT header has been corrupted.
70 *
71 ******************************************************************************/
72
73void acpi_tb_check_dsdt_header(void)
74{
75
76 /* Compare original length and checksum to current values */
77
78 if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
79 acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
80 ACPI_BIOS_ERROR((AE_INFO,
81 "The DSDT has been corrupted or replaced - "
82 "old, new headers below"));
83
84 acpi_tb_print_table_header(address: 0, header: &acpi_gbl_original_dsdt_header);
85 acpi_tb_print_table_header(address: 0, header: acpi_gbl_DSDT);
86
87 ACPI_ERROR((AE_INFO,
88 "Please send DMI info to linux-acpi@vger.kernel.org\n"
89 "If system does not work as expected, please boot with acpi=copy_dsdt"));
90
91 /* Disable further error messages */
92
93 acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
94 acpi_gbl_original_dsdt_header.checksum =
95 acpi_gbl_DSDT->checksum;
96 }
97}
98
99/*******************************************************************************
100 *
101 * FUNCTION: acpi_tb_copy_dsdt
102 *
103 * PARAMETERS: table_index - Index of installed table to copy
104 *
105 * RETURN: The copied DSDT
106 *
107 * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
108 * Some very bad BIOSs are known to either corrupt the DSDT or
109 * install a new, bad DSDT. This copy works around the problem.
110 *
111 ******************************************************************************/
112
113struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
114{
115 struct acpi_table_header *new_table;
116 struct acpi_table_desc *table_desc;
117
118 table_desc = &acpi_gbl_root_table_list.tables[table_index];
119
120 new_table = ACPI_ALLOCATE(table_desc->length);
121 if (!new_table) {
122 ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
123 table_desc->length));
124 return (NULL);
125 }
126
127 memcpy(to: new_table, from: table_desc->pointer, len: table_desc->length);
128 acpi_tb_uninstall_table(table_desc);
129
130 acpi_tb_init_table_descriptor(table_desc: &acpi_gbl_root_table_list.
131 tables[acpi_gbl_dsdt_index],
132 ACPI_PTR_TO_PHYSADDR(new_table),
133 ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
134 table: new_table);
135
136 ACPI_INFO(("Forced DSDT copy: length 0x%05X copied locally, original unmapped", new_table->length));
137
138 return (new_table);
139}
140
141/*******************************************************************************
142 *
143 * FUNCTION: acpi_tb_get_root_table_entry
144 *
145 * PARAMETERS: table_entry - Pointer to the RSDT/XSDT table entry
146 * table_entry_size - sizeof 32 or 64 (RSDT or XSDT)
147 *
148 * RETURN: Physical address extracted from the root table
149 *
150 * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
151 * both 32-bit and 64-bit platforms
152 *
153 * NOTE: acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
154 * 64-bit platforms.
155 *
156 ******************************************************************************/
157
158static acpi_physical_address
159acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
160{
161 u32 address32;
162 u64 address64;
163
164 /*
165 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
166 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
167 */
168 if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
169 /*
170 * 32-bit platform, RSDT: Return 32-bit table entry
171 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
172 */
173 ACPI_MOVE_32_TO_32(&address32, table_entry);
174 return address32;
175 } else {
176 /*
177 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
178 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
179 * return 64-bit
180 */
181 ACPI_MOVE_64_TO_64(&address64, table_entry);
182
183#if ACPI_MACHINE_WIDTH == 32
184 if (address64 > ACPI_UINT32_MAX) {
185
186 /* Will truncate 64-bit address to 32 bits, issue warning */
187
188 ACPI_BIOS_WARNING((AE_INFO,
189 "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
190 " truncating",
191 ACPI_FORMAT_UINT64(address64)));
192 }
193#endif
194 return ((acpi_physical_address)(address64));
195 }
196}
197
198/*******************************************************************************
199 *
200 * FUNCTION: acpi_tb_parse_root_table
201 *
202 * PARAMETERS: rsdp_address - Pointer to the RSDP
203 *
204 * RETURN: Status
205 *
206 * DESCRIPTION: This function is called to parse the Root System Description
207 * Table (RSDT or XSDT)
208 *
209 * NOTE: Tables are mapped (not copied) for efficiency. The FACS must
210 * be mapped and cannot be copied because it contains the actual
211 * memory location of the ACPI Global Lock.
212 *
213 ******************************************************************************/
214
215acpi_status ACPI_INIT_FUNCTION
216acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
217{
218 struct acpi_table_rsdp *rsdp;
219 u32 table_entry_size;
220 u32 i;
221 u32 table_count;
222 struct acpi_table_header *table;
223 acpi_physical_address address;
224 u32 length;
225 u8 *table_entry;
226 acpi_status status;
227 u32 table_index;
228
229 ACPI_FUNCTION_TRACE(tb_parse_root_table);
230
231 /* Map the entire RSDP and extract the address of the RSDT or XSDT */
232
233 rsdp = acpi_os_map_memory(where: rsdp_address, length: sizeof(struct acpi_table_rsdp));
234 if (!rsdp) {
235 return_ACPI_STATUS(AE_NO_MEMORY);
236 }
237
238 acpi_tb_print_table_header(address: rsdp_address,
239 ACPI_CAST_PTR(struct acpi_table_header,
240 rsdp));
241
242 /* Use XSDT if present and not overridden. Otherwise, use RSDT */
243
244 if ((rsdp->revision > 1) &&
245 rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
246 /*
247 * RSDP contains an XSDT (64-bit physical addresses). We must use
248 * the XSDT if the revision is > 1 and the XSDT pointer is present,
249 * as per the ACPI specification.
250 */
251 address = (acpi_physical_address)rsdp->xsdt_physical_address;
252 table_entry_size = ACPI_XSDT_ENTRY_SIZE;
253 } else {
254 /* Root table is an RSDT (32-bit physical addresses) */
255
256 address = (acpi_physical_address)rsdp->rsdt_physical_address;
257 table_entry_size = ACPI_RSDT_ENTRY_SIZE;
258 }
259
260 /*
261 * It is not possible to map more than one entry in some environments,
262 * so unmap the RSDP here before mapping other tables
263 */
264 acpi_os_unmap_memory(logical_address: rsdp, size: sizeof(struct acpi_table_rsdp));
265
266 /* Map the RSDT/XSDT table header to get the full table length */
267
268 table = acpi_os_map_memory(where: address, length: sizeof(struct acpi_table_header));
269 if (!table) {
270 return_ACPI_STATUS(AE_NO_MEMORY);
271 }
272
273 acpi_tb_print_table_header(address, header: table);
274
275 /*
276 * Validate length of the table, and map entire table.
277 * Minimum length table must contain at least one entry.
278 */
279 length = table->length;
280 acpi_os_unmap_memory(logical_address: table, size: sizeof(struct acpi_table_header));
281
282 if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
283 ACPI_BIOS_ERROR((AE_INFO,
284 "Invalid table length 0x%X in RSDT/XSDT",
285 length));
286 return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
287 }
288
289 table = acpi_os_map_memory(where: address, length);
290 if (!table) {
291 return_ACPI_STATUS(AE_NO_MEMORY);
292 }
293
294 /* Validate the root table checksum */
295
296 status = acpi_ut_verify_checksum(table, length);
297 if (ACPI_FAILURE(status)) {
298 acpi_os_unmap_memory(logical_address: table, size: length);
299 return_ACPI_STATUS(status);
300 }
301
302 /* Get the number of entries and pointer to first entry */
303
304 table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
305 table_entry_size);
306 table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
307
308 /* Initialize the root table array from the RSDT/XSDT */
309
310 for (i = 0; i < table_count; i++) {
311
312 /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
313
314 address =
315 acpi_tb_get_root_table_entry(table_entry, table_entry_size);
316
317 /* Skip NULL entries in RSDT/XSDT */
318
319 if (!address) {
320 goto next_table;
321 }
322
323 status = acpi_tb_install_standard_table(address,
324 ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
325 NULL, FALSE, TRUE,
326 table_index: &table_index);
327
328 if (ACPI_SUCCESS(status) &&
329 ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
330 tables[table_index].signature,
331 ACPI_SIG_FADT)) {
332 acpi_gbl_fadt_index = table_index;
333 acpi_tb_parse_fadt();
334 }
335
336next_table:
337
338 table_entry += table_entry_size;
339 }
340
341 acpi_os_unmap_memory(logical_address: table, size: length);
342 return_ACPI_STATUS(AE_OK);
343}
344
345/*******************************************************************************
346 *
347 * FUNCTION: acpi_tb_get_table
348 *
349 * PARAMETERS: table_desc - Table descriptor
350 * out_table - Where the pointer to the table is returned
351 *
352 * RETURN: Status and pointer to the requested table
353 *
354 * DESCRIPTION: Increase a reference to a table descriptor and return the
355 * validated table pointer.
356 * If the table descriptor is an entry of the root table list,
357 * this API must be invoked with ACPI_MTX_TABLES acquired.
358 *
359 ******************************************************************************/
360
361acpi_status
362acpi_tb_get_table(struct acpi_table_desc *table_desc,
363 struct acpi_table_header **out_table)
364{
365 acpi_status status;
366
367 ACPI_FUNCTION_TRACE(acpi_tb_get_table);
368
369 if (table_desc->validation_count == 0) {
370
371 /* Table need to be "VALIDATED" */
372
373 status = acpi_tb_validate_table(table_desc);
374 if (ACPI_FAILURE(status)) {
375 return_ACPI_STATUS(status);
376 }
377 }
378
379 if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
380 table_desc->validation_count++;
381
382 /*
383 * Detect validation_count overflows to ensure that the warning
384 * message will only be printed once.
385 */
386 if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
387 ACPI_WARNING((AE_INFO,
388 "Table %p, Validation count overflows\n",
389 table_desc));
390 }
391 }
392
393 *out_table = table_desc->pointer;
394 return_ACPI_STATUS(AE_OK);
395}
396
397/*******************************************************************************
398 *
399 * FUNCTION: acpi_tb_put_table
400 *
401 * PARAMETERS: table_desc - Table descriptor
402 *
403 * RETURN: None
404 *
405 * DESCRIPTION: Decrease a reference to a table descriptor and release the
406 * validated table pointer if no references.
407 * If the table descriptor is an entry of the root table list,
408 * this API must be invoked with ACPI_MTX_TABLES acquired.
409 *
410 ******************************************************************************/
411
412void acpi_tb_put_table(struct acpi_table_desc *table_desc)
413{
414
415 ACPI_FUNCTION_TRACE(acpi_tb_put_table);
416
417 if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
418 table_desc->validation_count--;
419
420 /*
421 * Detect validation_count underflows to ensure that the warning
422 * message will only be printed once.
423 */
424 if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
425 ACPI_WARNING((AE_INFO,
426 "Table %p, Validation count underflows\n",
427 table_desc));
428 return_VOID;
429 }
430 }
431
432 if (table_desc->validation_count == 0) {
433
434 /* Table need to be "INVALIDATED" */
435
436 acpi_tb_invalidate_table(table_desc);
437 }
438
439 return_VOID;
440}
441