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 - 2023, 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#if (!ACPI_REDUCED_HARDWARE)
22/*******************************************************************************
23 *
24 * FUNCTION:    acpi_tb_initialize_facs
25 *
26 * PARAMETERS:  None
27 *
28 * RETURN:      Status
29 *
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
32 *
33 ******************************************************************************/
34
35acpi_status acpi_tb_initialize_facs(void)
36{
37	struct acpi_table_facs *facs;
38
39	/* If Hardware Reduced flag is set, there is no FACS */
40
41	if (acpi_gbl_reduced_hardware) {
42		acpi_gbl_FACS = NULL;
43		return (AE_OK);
44	} else if (acpi_gbl_FADT.Xfacs &&
45		   (!acpi_gbl_FADT.facs
46		    || !acpi_gbl_use32_bit_facs_addresses)) {
47		(void)acpi_get_table_by_index(acpi_gbl_xfacs_index,
48					      ACPI_CAST_INDIRECT_PTR(struct
49								     acpi_table_header,
50								     &facs));
51		acpi_gbl_FACS = facs;
52	} else if (acpi_gbl_FADT.facs) {
53		(void)acpi_get_table_by_index(acpi_gbl_facs_index,
54					      ACPI_CAST_INDIRECT_PTR(struct
55								     acpi_table_header,
56								     &facs));
57		acpi_gbl_FACS = facs;
58	}
59
60	/* If there is no FACS, just continue. There was already an error msg */
61
62	return (AE_OK);
63}
64#endif				/* !ACPI_REDUCED_HARDWARE */
65
66/*******************************************************************************
67 *
68 * FUNCTION:    acpi_tb_check_dsdt_header
69 *
70 * PARAMETERS:  None
71 *
72 * RETURN:      None
73 *
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.
77 *
78 ******************************************************************************/
79
80void acpi_tb_check_dsdt_header(void)
81{
82
83	/* Compare original length and checksum to current values */
84
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"));
90
91		acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
92		acpi_tb_print_table_header(0, acpi_gbl_DSDT);
93
94		ACPI_ERROR((AE_INFO,
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"));
97
98		/* Disable further error messages */
99
100		acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
101		acpi_gbl_original_dsdt_header.checksum =
102		    acpi_gbl_DSDT->checksum;
103	}
104}
105
106/*******************************************************************************
107 *
108 * FUNCTION:    acpi_tb_copy_dsdt
109 *
110 * PARAMETERS:  table_index         - Index of installed table to copy
111 *
112 * RETURN:      The copied DSDT
113 *
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.
117 *
118 ******************************************************************************/
119
120struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
121{
122	struct acpi_table_header *new_table;
123	struct acpi_table_desc *table_desc;
124
125	table_desc = &acpi_gbl_root_table_list.tables[table_index];
126
127	new_table = ACPI_ALLOCATE(table_desc->length);
128	if (!new_table) {
129		ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
130			    table_desc->length));
131		return (NULL);
132	}
133
134	memcpy(new_table, table_desc->pointer, table_desc->length);
135	acpi_tb_uninstall_table(table_desc);
136
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,
141				      new_table);
142
143	ACPI_INFO(("Forced DSDT copy: length 0x%05X copied locally, original unmapped", new_table->length));
144
145	return (new_table);
146}
147
148/*******************************************************************************
149 *
150 * FUNCTION:    acpi_tb_get_root_table_entry
151 *
152 * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
153 *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
154 *
155 * RETURN:      Physical address extracted from the root table
156 *
157 * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
158 *              both 32-bit and 64-bit platforms
159 *
160 * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
161 *              64-bit platforms.
162 *
163 ******************************************************************************/
164
165static acpi_physical_address
166acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
167{
168	u32 address32;
169	u64 address64;
170
171	/*
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
174	 */
175	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
176		/*
177		 * 32-bit platform, RSDT: Return 32-bit table entry
178		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
179		 */
180		ACPI_MOVE_32_TO_32(&address32, table_entry);
181		return address32;
182	} else {
183		/*
184		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
185		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
186		 *  return 64-bit
187		 */
188		ACPI_MOVE_64_TO_64(&address64, table_entry);
189
190#if ACPI_MACHINE_WIDTH == 32
191		if (address64 > ACPI_UINT32_MAX) {
192
193			/* Will truncate 64-bit address to 32 bits, issue warning */
194
195			ACPI_BIOS_WARNING((AE_INFO,
196					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
197					   " truncating",
198					   ACPI_FORMAT_UINT64(address64)));
199		}
200#endif
201		return ((acpi_physical_address)(address64));
202	}
203}
204
205/*******************************************************************************
206 *
207 * FUNCTION:    acpi_tb_parse_root_table
208 *
209 * PARAMETERS:  rsdp_address        - Pointer to the RSDP
210 *
211 * RETURN:      Status
212 *
213 * DESCRIPTION: This function is called to parse the Root System Description
214 *              Table (RSDT or XSDT)
215 *
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.
219 *
220 ******************************************************************************/
221
222acpi_status ACPI_INIT_FUNCTION
223acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
224{
225	struct acpi_table_rsdp *rsdp;
226	u32 table_entry_size;
227	u32 i;
228	u32 table_count;
229	struct acpi_table_header *table;
230	acpi_physical_address address;
231	u32 length;
232	u8 *table_entry;
233	acpi_status status;
234	u32 table_index;
235
236	ACPI_FUNCTION_TRACE(tb_parse_root_table);
237
238	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
239
240	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
241	if (!rsdp) {
242		return_ACPI_STATUS(AE_NO_MEMORY);
243	}
244
245	acpi_tb_print_table_header(rsdp_address,
246				   ACPI_CAST_PTR(struct acpi_table_header,
247						 rsdp));
248
249	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
250
251	if ((rsdp->revision > 1) &&
252	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
253		/*
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.
257		 */
258		address = (acpi_physical_address)rsdp->xsdt_physical_address;
259		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
260	} else {
261		/* Root table is an RSDT (32-bit physical addresses) */
262
263		address = (acpi_physical_address)rsdp->rsdt_physical_address;
264		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
265	}
266
267	/*
268	 * It is not possible to map more than one entry in some environments,
269	 * so unmap the RSDP here before mapping other tables
270	 */
271	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
272
273	/* Map the RSDT/XSDT table header to get the full table length */
274
275	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
276	if (!table) {
277		return_ACPI_STATUS(AE_NO_MEMORY);
278	}
279
280	acpi_tb_print_table_header(address, table);
281
282	/*
283	 * Validate length of the table, and map entire table.
284	 * Minimum length table must contain at least one entry.
285	 */
286	length = table->length;
287	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
288
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",
292				 length));
293		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
294	}
295
296	table = acpi_os_map_memory(address, length);
297	if (!table) {
298		return_ACPI_STATUS(AE_NO_MEMORY);
299	}
300
301	/* Validate the root table checksum */
302
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);
307	}
308
309	/* Get the number of entries and pointer to first entry */
310
311	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
312			    table_entry_size);
313	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
314
315	/* Initialize the root table array from the RSDT/XSDT */
316
317	for (i = 0; i < table_count; i++) {
318
319		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
320
321		address =
322		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
323
324		/* Skip NULL entries in RSDT/XSDT */
325
326		if (!address) {
327			goto next_table;
328		}
329
330		status = acpi_tb_install_standard_table(address,
331							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
332							NULL, FALSE, TRUE,
333							&table_index);
334
335		if (ACPI_SUCCESS(status) &&
336		    ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
337					 tables[table_index].signature,
338					 ACPI_SIG_FADT)) {
339			acpi_gbl_fadt_index = table_index;
340			acpi_tb_parse_fadt();
341		}
342
343next_table:
344
345		table_entry += table_entry_size;
346	}
347
348	acpi_os_unmap_memory(table, length);
349	return_ACPI_STATUS(AE_OK);
350}
351
352/*******************************************************************************
353 *
354 * FUNCTION:    acpi_tb_get_table
355 *
356 * PARAMETERS:  table_desc          - Table descriptor
357 *              out_table           - Where the pointer to the table is returned
358 *
359 * RETURN:      Status and pointer to the requested table
360 *
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.
365 *
366 ******************************************************************************/
367
368acpi_status
369acpi_tb_get_table(struct acpi_table_desc *table_desc,
370		  struct acpi_table_header **out_table)
371{
372	acpi_status status;
373
374	ACPI_FUNCTION_TRACE(acpi_tb_get_table);
375
376	if (table_desc->validation_count == 0) {
377
378		/* Table need to be "VALIDATED" */
379
380		status = acpi_tb_validate_table(table_desc);
381		if (ACPI_FAILURE(status)) {
382			return_ACPI_STATUS(status);
383		}
384	}
385
386	if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
387		table_desc->validation_count++;
388
389		/*
390		 * Detect validation_count overflows to ensure that the warning
391		 * message will only be printed once.
392		 */
393		if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
394			ACPI_WARNING((AE_INFO,
395				      "Table %p, Validation count overflows\n",
396				      table_desc));
397		}
398	}
399
400	*out_table = table_desc->pointer;
401	return_ACPI_STATUS(AE_OK);
402}
403
404/*******************************************************************************
405 *
406 * FUNCTION:    acpi_tb_put_table
407 *
408 * PARAMETERS:  table_desc          - Table descriptor
409 *
410 * RETURN:      None
411 *
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.
416 *
417 ******************************************************************************/
418
419void acpi_tb_put_table(struct acpi_table_desc *table_desc)
420{
421
422	ACPI_FUNCTION_TRACE(acpi_tb_put_table);
423
424	if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
425		table_desc->validation_count--;
426
427		/*
428		 * Detect validation_count underflows to ensure that the warning
429		 * message will only be printed once.
430		 */
431		if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
432			ACPI_WARNING((AE_INFO,
433				      "Table %p, Validation count underflows\n",
434				      table_desc));
435			return_VOID;
436		}
437	}
438
439	if (table_desc->validation_count == 0) {
440
441		/* Table need to be "INVALIDATED" */
442
443		acpi_tb_invalidate_table(table_desc);
444	}
445
446	return_VOID;
447}
448