xref: /openbmc/linux/drivers/acpi/acpica/tbutils.c (revision d56ba92b)
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
15 ACPI_MODULE_NAME("tbutils")
16 
17 /* Local prototypes */
18 static acpi_physical_address
19 acpi_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 
acpi_tb_initialize_facs(void)35 acpi_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 
acpi_tb_check_dsdt_header(void)80 void 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 
acpi_tb_copy_dsdt(u32 table_index)120 struct 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 
165 static acpi_physical_address
acpi_tb_get_root_table_entry(u8 * table_entry,u32 table_entry_size)166 acpi_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 
222 acpi_status ACPI_INIT_FUNCTION
acpi_tb_parse_root_table(acpi_physical_address rsdp_address)223 acpi_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 
343 next_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 
368 acpi_status
acpi_tb_get_table(struct acpi_table_desc * table_desc,struct acpi_table_header ** out_table)369 acpi_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 
acpi_tb_put_table(struct acpi_table_desc * table_desc)419 void 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