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 - 2022, 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 	u64 address64;
169 
170 	/*
171 	 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
172 	 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
173 	 */
174 	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
175 		/*
176 		 * 32-bit platform, RSDT: Return 32-bit table entry
177 		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
178 		 */
179 		return ((acpi_physical_address)
180 			(*ACPI_CAST_PTR(u32, table_entry)));
181 	} else {
182 		/*
183 		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
184 		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
185 		 *  return 64-bit
186 		 */
187 		ACPI_MOVE_64_TO_64(&address64, table_entry);
188 
189 #if ACPI_MACHINE_WIDTH == 32
190 		if (address64 > ACPI_UINT32_MAX) {
191 
192 			/* Will truncate 64-bit address to 32 bits, issue warning */
193 
194 			ACPI_BIOS_WARNING((AE_INFO,
195 					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
196 					   " truncating",
197 					   ACPI_FORMAT_UINT64(address64)));
198 		}
199 #endif
200 		return ((acpi_physical_address)(address64));
201 	}
202 }
203 
204 /*******************************************************************************
205  *
206  * FUNCTION:    acpi_tb_parse_root_table
207  *
208  * PARAMETERS:  rsdp_address        - Pointer to the RSDP
209  *
210  * RETURN:      Status
211  *
212  * DESCRIPTION: This function is called to parse the Root System Description
213  *              Table (RSDT or XSDT)
214  *
215  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
216  *              be mapped and cannot be copied because it contains the actual
217  *              memory location of the ACPI Global Lock.
218  *
219  ******************************************************************************/
220 
221 acpi_status ACPI_INIT_FUNCTION
acpi_tb_parse_root_table(acpi_physical_address rsdp_address)222 acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
223 {
224 	struct acpi_table_rsdp *rsdp;
225 	u32 table_entry_size;
226 	u32 i;
227 	u32 table_count;
228 	struct acpi_table_header *table;
229 	acpi_physical_address address;
230 	u32 length;
231 	u8 *table_entry;
232 	acpi_status status;
233 	u32 table_index;
234 
235 	ACPI_FUNCTION_TRACE(tb_parse_root_table);
236 
237 	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
238 
239 	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
240 	if (!rsdp) {
241 		return_ACPI_STATUS(AE_NO_MEMORY);
242 	}
243 
244 	acpi_tb_print_table_header(rsdp_address,
245 				   ACPI_CAST_PTR(struct acpi_table_header,
246 						 rsdp));
247 
248 	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
249 
250 	if ((rsdp->revision > 1) &&
251 	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
252 		/*
253 		 * RSDP contains an XSDT (64-bit physical addresses). We must use
254 		 * the XSDT if the revision is > 1 and the XSDT pointer is present,
255 		 * as per the ACPI specification.
256 		 */
257 		address = (acpi_physical_address)rsdp->xsdt_physical_address;
258 		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
259 	} else {
260 		/* Root table is an RSDT (32-bit physical addresses) */
261 
262 		address = (acpi_physical_address)rsdp->rsdt_physical_address;
263 		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
264 	}
265 
266 	/*
267 	 * It is not possible to map more than one entry in some environments,
268 	 * so unmap the RSDP here before mapping other tables
269 	 */
270 	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
271 
272 	/* Map the RSDT/XSDT table header to get the full table length */
273 
274 	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
275 	if (!table) {
276 		return_ACPI_STATUS(AE_NO_MEMORY);
277 	}
278 
279 	acpi_tb_print_table_header(address, table);
280 
281 	/*
282 	 * Validate length of the table, and map entire table.
283 	 * Minimum length table must contain at least one entry.
284 	 */
285 	length = table->length;
286 	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
287 
288 	if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
289 		ACPI_BIOS_ERROR((AE_INFO,
290 				 "Invalid table length 0x%X in RSDT/XSDT",
291 				 length));
292 		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
293 	}
294 
295 	table = acpi_os_map_memory(address, length);
296 	if (!table) {
297 		return_ACPI_STATUS(AE_NO_MEMORY);
298 	}
299 
300 	/* Validate the root table checksum */
301 
302 	status = acpi_ut_verify_checksum(table, length);
303 	if (ACPI_FAILURE(status)) {
304 		acpi_os_unmap_memory(table, length);
305 		return_ACPI_STATUS(status);
306 	}
307 
308 	/* Get the number of entries and pointer to first entry */
309 
310 	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
311 			    table_entry_size);
312 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
313 
314 	/* Initialize the root table array from the RSDT/XSDT */
315 
316 	for (i = 0; i < table_count; i++) {
317 
318 		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
319 
320 		address =
321 		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
322 
323 		/* Skip NULL entries in RSDT/XSDT */
324 
325 		if (!address) {
326 			goto next_table;
327 		}
328 
329 		status = acpi_tb_install_standard_table(address,
330 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
331 							NULL, FALSE, TRUE,
332 							&table_index);
333 
334 		if (ACPI_SUCCESS(status) &&
335 		    ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
336 					 tables[table_index].signature,
337 					 ACPI_SIG_FADT)) {
338 			acpi_gbl_fadt_index = table_index;
339 			acpi_tb_parse_fadt();
340 		}
341 
342 next_table:
343 
344 		table_entry += table_entry_size;
345 	}
346 
347 	acpi_os_unmap_memory(table, length);
348 	return_ACPI_STATUS(AE_OK);
349 }
350 
351 /*******************************************************************************
352  *
353  * FUNCTION:    acpi_tb_get_table
354  *
355  * PARAMETERS:  table_desc          - Table descriptor
356  *              out_table           - Where the pointer to the table is returned
357  *
358  * RETURN:      Status and pointer to the requested table
359  *
360  * DESCRIPTION: Increase a reference to a table descriptor and return the
361  *              validated table pointer.
362  *              If the table descriptor is an entry of the root table list,
363  *              this API must be invoked with ACPI_MTX_TABLES acquired.
364  *
365  ******************************************************************************/
366 
367 acpi_status
acpi_tb_get_table(struct acpi_table_desc * table_desc,struct acpi_table_header ** out_table)368 acpi_tb_get_table(struct acpi_table_desc *table_desc,
369 		  struct acpi_table_header **out_table)
370 {
371 	acpi_status status;
372 
373 	ACPI_FUNCTION_TRACE(acpi_tb_get_table);
374 
375 	if (table_desc->validation_count == 0) {
376 
377 		/* Table need to be "VALIDATED" */
378 
379 		status = acpi_tb_validate_table(table_desc);
380 		if (ACPI_FAILURE(status)) {
381 			return_ACPI_STATUS(status);
382 		}
383 	}
384 
385 	if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
386 		table_desc->validation_count++;
387 
388 		/*
389 		 * Detect validation_count overflows to ensure that the warning
390 		 * message will only be printed once.
391 		 */
392 		if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
393 			ACPI_WARNING((AE_INFO,
394 				      "Table %p, Validation count overflows\n",
395 				      table_desc));
396 		}
397 	}
398 
399 	*out_table = table_desc->pointer;
400 	return_ACPI_STATUS(AE_OK);
401 }
402 
403 /*******************************************************************************
404  *
405  * FUNCTION:    acpi_tb_put_table
406  *
407  * PARAMETERS:  table_desc          - Table descriptor
408  *
409  * RETURN:      None
410  *
411  * DESCRIPTION: Decrease a reference to a table descriptor and release the
412  *              validated table pointer if no references.
413  *              If the table descriptor is an entry of the root table list,
414  *              this API must be invoked with ACPI_MTX_TABLES acquired.
415  *
416  ******************************************************************************/
417 
acpi_tb_put_table(struct acpi_table_desc * table_desc)418 void acpi_tb_put_table(struct acpi_table_desc *table_desc)
419 {
420 
421 	ACPI_FUNCTION_TRACE(acpi_tb_put_table);
422 
423 	if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
424 		table_desc->validation_count--;
425 
426 		/*
427 		 * Detect validation_count underflows to ensure that the warning
428 		 * message will only be printed once.
429 		 */
430 		if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
431 			ACPI_WARNING((AE_INFO,
432 				      "Table %p, Validation count underflows\n",
433 				      table_desc));
434 			return_VOID;
435 		}
436 	}
437 
438 	if (table_desc->validation_count == 0) {
439 
440 		/* Table need to be "INVALIDATED" */
441 
442 		acpi_tb_invalidate_table(table_desc);
443 	}
444 
445 	return_VOID;
446 }
447