1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
4 * Module Name: tbutils - ACPI Table utilities
6 * Copyright (C) 2000 - 2023, Intel Corp.
8 *****************************************************************************/
10 #include <acpi/acpi.h>
14 #define _COMPONENT ACPI_TABLES
15 ACPI_MODULE_NAME("tbutils")
17 /* Local prototypes */
18 static acpi_physical_address
19 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
21 #if (!ACPI_REDUCED_HARDWARE)
22 /*******************************************************************************
24 * FUNCTION: acpi_tb_initialize_facs
30 * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
31 * for accessing the Global Lock and Firmware Waking Vector
33 ******************************************************************************/
35 acpi_status acpi_tb_initialize_facs(void)
37 struct acpi_table_facs *facs;
39 /* If Hardware Reduced flag is set, there is no FACS */
41 if (acpi_gbl_reduced_hardware) {
44 } else if (acpi_gbl_FADT.Xfacs &&
46 || !acpi_gbl_use32_bit_facs_addresses)) {
47 (void)acpi_get_table_by_index(acpi_gbl_xfacs_index,
48 ACPI_CAST_INDIRECT_PTR(struct
52 } else if (acpi_gbl_FADT.facs) {
53 (void)acpi_get_table_by_index(acpi_gbl_facs_index,
54 ACPI_CAST_INDIRECT_PTR(struct
60 /* If there is no FACS, just continue. There was already an error msg */
64 #endif /* !ACPI_REDUCED_HARDWARE */
66 /*******************************************************************************
68 * FUNCTION: acpi_tb_check_dsdt_header
74 * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
75 * if the DSDT has been replaced from outside the OS and/or if
76 * the DSDT header has been corrupted.
78 ******************************************************************************/
80 void acpi_tb_check_dsdt_header(void)
83 /* Compare original length and checksum to current values */
85 if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
86 acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
87 ACPI_BIOS_ERROR((AE_INFO,
88 "The DSDT has been corrupted or replaced - "
89 "old, new headers below"));
91 acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
92 acpi_tb_print_table_header(0, acpi_gbl_DSDT);
95 "Please send DMI info to linux-acpi@vger.kernel.org\n"
96 "If system does not work as expected, please boot with acpi=copy_dsdt"));
98 /* Disable further error messages */
100 acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
101 acpi_gbl_original_dsdt_header.checksum =
102 acpi_gbl_DSDT->checksum;
106 /*******************************************************************************
108 * FUNCTION: acpi_tb_copy_dsdt
110 * PARAMETERS: table_index - Index of installed table to copy
112 * RETURN: The copied DSDT
114 * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
115 * Some very bad BIOSs are known to either corrupt the DSDT or
116 * install a new, bad DSDT. This copy works around the problem.
118 ******************************************************************************/
120 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
122 struct acpi_table_header *new_table;
123 struct acpi_table_desc *table_desc;
125 table_desc = &acpi_gbl_root_table_list.tables[table_index];
127 new_table = ACPI_ALLOCATE(table_desc->length);
129 ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
130 table_desc->length));
134 memcpy(new_table, table_desc->pointer, table_desc->length);
135 acpi_tb_uninstall_table(table_desc);
137 acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.
138 tables[acpi_gbl_dsdt_index],
139 ACPI_PTR_TO_PHYSADDR(new_table),
140 ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
143 ACPI_INFO(("Forced DSDT copy: length 0x%05X copied locally, original unmapped", new_table->length));
148 /*******************************************************************************
150 * FUNCTION: acpi_tb_get_root_table_entry
152 * PARAMETERS: table_entry - Pointer to the RSDT/XSDT table entry
153 * table_entry_size - sizeof 32 or 64 (RSDT or XSDT)
155 * RETURN: Physical address extracted from the root table
157 * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
158 * both 32-bit and 64-bit platforms
160 * NOTE: acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
163 ******************************************************************************/
165 static acpi_physical_address
166 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
172 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
173 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
175 if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
177 * 32-bit platform, RSDT: Return 32-bit table entry
178 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
180 ACPI_MOVE_32_TO_32(&address32, table_entry);
184 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
185 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
188 ACPI_MOVE_64_TO_64(&address64, table_entry);
190 #if ACPI_MACHINE_WIDTH == 32
191 if (address64 > ACPI_UINT32_MAX) {
193 /* Will truncate 64-bit address to 32 bits, issue warning */
195 ACPI_BIOS_WARNING((AE_INFO,
196 "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
198 ACPI_FORMAT_UINT64(address64)));
201 return ((acpi_physical_address)(address64));
205 /*******************************************************************************
207 * FUNCTION: acpi_tb_parse_root_table
209 * PARAMETERS: rsdp_address - Pointer to the RSDP
213 * DESCRIPTION: This function is called to parse the Root System Description
214 * Table (RSDT or XSDT)
216 * NOTE: Tables are mapped (not copied) for efficiency. The FACS must
217 * be mapped and cannot be copied because it contains the actual
218 * memory location of the ACPI Global Lock.
220 ******************************************************************************/
222 acpi_status ACPI_INIT_FUNCTION
223 acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
225 struct acpi_table_rsdp *rsdp;
226 u32 table_entry_size;
229 struct acpi_table_header *table;
230 acpi_physical_address address;
236 ACPI_FUNCTION_TRACE(tb_parse_root_table);
238 /* Map the entire RSDP and extract the address of the RSDT or XSDT */
240 rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
242 return_ACPI_STATUS(AE_NO_MEMORY);
245 acpi_tb_print_table_header(rsdp_address,
246 ACPI_CAST_PTR(struct acpi_table_header,
249 /* Use XSDT if present and not overridden. Otherwise, use RSDT */
251 if ((rsdp->revision > 1) &&
252 rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
254 * RSDP contains an XSDT (64-bit physical addresses). We must use
255 * the XSDT if the revision is > 1 and the XSDT pointer is present,
256 * as per the ACPI specification.
258 address = (acpi_physical_address)rsdp->xsdt_physical_address;
259 table_entry_size = ACPI_XSDT_ENTRY_SIZE;
261 /* Root table is an RSDT (32-bit physical addresses) */
263 address = (acpi_physical_address)rsdp->rsdt_physical_address;
264 table_entry_size = ACPI_RSDT_ENTRY_SIZE;
268 * It is not possible to map more than one entry in some environments,
269 * so unmap the RSDP here before mapping other tables
271 acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
273 /* Map the RSDT/XSDT table header to get the full table length */
275 table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
277 return_ACPI_STATUS(AE_NO_MEMORY);
280 acpi_tb_print_table_header(address, table);
283 * Validate length of the table, and map entire table.
284 * Minimum length table must contain at least one entry.
286 length = table->length;
287 acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
289 if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
290 ACPI_BIOS_ERROR((AE_INFO,
291 "Invalid table length 0x%X in RSDT/XSDT",
293 return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
296 table = acpi_os_map_memory(address, length);
298 return_ACPI_STATUS(AE_NO_MEMORY);
301 /* Validate the root table checksum */
303 status = acpi_ut_verify_checksum(table, length);
304 if (ACPI_FAILURE(status)) {
305 acpi_os_unmap_memory(table, length);
306 return_ACPI_STATUS(status);
309 /* Get the number of entries and pointer to first entry */
311 table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
313 table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
315 /* Initialize the root table array from the RSDT/XSDT */
317 for (i = 0; i < table_count; i++) {
319 /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
322 acpi_tb_get_root_table_entry(table_entry, table_entry_size);
324 /* Skip NULL entries in RSDT/XSDT */
330 status = acpi_tb_install_standard_table(address,
331 ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
335 if (ACPI_SUCCESS(status) &&
336 ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
337 tables[table_index].signature,
339 acpi_gbl_fadt_index = table_index;
340 acpi_tb_parse_fadt();
345 table_entry += table_entry_size;
348 acpi_os_unmap_memory(table, length);
349 return_ACPI_STATUS(AE_OK);
352 /*******************************************************************************
354 * FUNCTION: acpi_tb_get_table
356 * PARAMETERS: table_desc - Table descriptor
357 * out_table - Where the pointer to the table is returned
359 * RETURN: Status and pointer to the requested table
361 * DESCRIPTION: Increase a reference to a table descriptor and return the
362 * validated table pointer.
363 * If the table descriptor is an entry of the root table list,
364 * this API must be invoked with ACPI_MTX_TABLES acquired.
366 ******************************************************************************/
369 acpi_tb_get_table(struct acpi_table_desc *table_desc,
370 struct acpi_table_header **out_table)
374 ACPI_FUNCTION_TRACE(acpi_tb_get_table);
376 if (table_desc->validation_count == 0) {
378 /* Table need to be "VALIDATED" */
380 status = acpi_tb_validate_table(table_desc);
381 if (ACPI_FAILURE(status)) {
382 return_ACPI_STATUS(status);
386 if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
387 table_desc->validation_count++;
390 * Detect validation_count overflows to ensure that the warning
391 * message will only be printed once.
393 if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
394 ACPI_WARNING((AE_INFO,
395 "Table %p, Validation count overflows\n",
400 *out_table = table_desc->pointer;
401 return_ACPI_STATUS(AE_OK);
404 /*******************************************************************************
406 * FUNCTION: acpi_tb_put_table
408 * PARAMETERS: table_desc - Table descriptor
412 * DESCRIPTION: Decrease a reference to a table descriptor and release the
413 * validated table pointer if no references.
414 * If the table descriptor is an entry of the root table list,
415 * this API must be invoked with ACPI_MTX_TABLES acquired.
417 ******************************************************************************/
419 void acpi_tb_put_table(struct acpi_table_desc *table_desc)
422 ACPI_FUNCTION_TRACE(acpi_tb_put_table);
424 if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
425 table_desc->validation_count--;
428 * Detect validation_count underflows to ensure that the warning
429 * message will only be printed once.
431 if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
432 ACPI_WARNING((AE_INFO,
433 "Table %p, Validation count underflows\n",
439 if (table_desc->validation_count == 0) {
441 /* Table need to be "INVALIDATED" */
443 acpi_tb_invalidate_table(table_desc);