xref: /openbmc/linux/drivers/acpi/acpica/tbutils.c (revision aac5987a)
1 /******************************************************************************
2  *
3  * Module Name: tbutils - ACPI Table utilities
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "actables.h"
47 
48 #define _COMPONENT          ACPI_TABLES
49 ACPI_MODULE_NAME("tbutils")
50 
51 /* Local prototypes */
52 static acpi_physical_address
53 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
54 
55 #if (!ACPI_REDUCED_HARDWARE)
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_tb_initialize_facs
59  *
60  * PARAMETERS:  None
61  *
62  * RETURN:      Status
63  *
64  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
65  *              for accessing the Global Lock and Firmware Waking Vector
66  *
67  ******************************************************************************/
68 
69 acpi_status acpi_tb_initialize_facs(void)
70 {
71 	struct acpi_table_facs *facs;
72 
73 	/* If Hardware Reduced flag is set, there is no FACS */
74 
75 	if (acpi_gbl_reduced_hardware) {
76 		acpi_gbl_FACS = NULL;
77 		return (AE_OK);
78 	} else if (acpi_gbl_FADT.Xfacs &&
79 		   (!acpi_gbl_FADT.facs
80 		    || !acpi_gbl_use32_bit_facs_addresses)) {
81 		(void)acpi_get_table_by_index(acpi_gbl_xfacs_index,
82 					      ACPI_CAST_INDIRECT_PTR(struct
83 								     acpi_table_header,
84 								     &facs));
85 		acpi_gbl_FACS = facs;
86 	} else if (acpi_gbl_FADT.facs) {
87 		(void)acpi_get_table_by_index(acpi_gbl_facs_index,
88 					      ACPI_CAST_INDIRECT_PTR(struct
89 								     acpi_table_header,
90 								     &facs));
91 		acpi_gbl_FACS = facs;
92 	}
93 
94 	/* If there is no FACS, just continue. There was already an error msg */
95 
96 	return (AE_OK);
97 }
98 #endif				/* !ACPI_REDUCED_HARDWARE */
99 
100 /*******************************************************************************
101  *
102  * FUNCTION:    acpi_tb_check_dsdt_header
103  *
104  * PARAMETERS:  None
105  *
106  * RETURN:      None
107  *
108  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
109  *              if the DSDT has been replaced from outside the OS and/or if
110  *              the DSDT header has been corrupted.
111  *
112  ******************************************************************************/
113 
114 void acpi_tb_check_dsdt_header(void)
115 {
116 
117 	/* Compare original length and checksum to current values */
118 
119 	if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
120 	    acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
121 		ACPI_BIOS_ERROR((AE_INFO,
122 				 "The DSDT has been corrupted or replaced - "
123 				 "old, new headers below"));
124 
125 		acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
126 		acpi_tb_print_table_header(0, acpi_gbl_DSDT);
127 
128 		ACPI_ERROR((AE_INFO,
129 			    "Please send DMI info to linux-acpi@vger.kernel.org\n"
130 			    "If system does not work as expected, please boot with acpi=copy_dsdt"));
131 
132 		/* Disable further error messages */
133 
134 		acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
135 		acpi_gbl_original_dsdt_header.checksum =
136 		    acpi_gbl_DSDT->checksum;
137 	}
138 }
139 
140 /*******************************************************************************
141  *
142  * FUNCTION:    acpi_tb_copy_dsdt
143  *
144  * PARAMETERS:  table_desc          - Installed table to copy
145  *
146  * RETURN:      None
147  *
148  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
149  *              Some very bad BIOSs are known to either corrupt the DSDT or
150  *              install a new, bad DSDT. This copy works around the problem.
151  *
152  ******************************************************************************/
153 
154 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
155 {
156 	struct acpi_table_header *new_table;
157 	struct acpi_table_desc *table_desc;
158 
159 	table_desc = &acpi_gbl_root_table_list.tables[table_index];
160 
161 	new_table = ACPI_ALLOCATE(table_desc->length);
162 	if (!new_table) {
163 		ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
164 			    table_desc->length));
165 		return (NULL);
166 	}
167 
168 	memcpy(new_table, table_desc->pointer, table_desc->length);
169 	acpi_tb_uninstall_table(table_desc);
170 
171 	acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.
172 				      tables[acpi_gbl_dsdt_index],
173 				      ACPI_PTR_TO_PHYSADDR(new_table),
174 				      ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
175 				      new_table);
176 
177 	ACPI_INFO(("Forced DSDT copy: length 0x%05X copied locally, original unmapped", new_table->length));
178 
179 	return (new_table);
180 }
181 
182 /*******************************************************************************
183  *
184  * FUNCTION:    acpi_tb_get_root_table_entry
185  *
186  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
187  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
188  *
189  * RETURN:      Physical address extracted from the root table
190  *
191  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
192  *              both 32-bit and 64-bit platforms
193  *
194  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
195  *              64-bit platforms.
196  *
197  ******************************************************************************/
198 
199 static acpi_physical_address
200 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
201 {
202 	u64 address64;
203 
204 	/*
205 	 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
206 	 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
207 	 */
208 	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
209 		/*
210 		 * 32-bit platform, RSDT: Return 32-bit table entry
211 		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
212 		 */
213 		return ((acpi_physical_address)
214 			(*ACPI_CAST_PTR(u32, table_entry)));
215 	} else {
216 		/*
217 		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
218 		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
219 		 *  return 64-bit
220 		 */
221 		ACPI_MOVE_64_TO_64(&address64, table_entry);
222 
223 #if ACPI_MACHINE_WIDTH == 32
224 		if (address64 > ACPI_UINT32_MAX) {
225 
226 			/* Will truncate 64-bit address to 32 bits, issue warning */
227 
228 			ACPI_BIOS_WARNING((AE_INFO,
229 					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
230 					   " truncating",
231 					   ACPI_FORMAT_UINT64(address64)));
232 		}
233 #endif
234 		return ((acpi_physical_address)(address64));
235 	}
236 }
237 
238 /*******************************************************************************
239  *
240  * FUNCTION:    acpi_tb_parse_root_table
241  *
242  * PARAMETERS:  rsdp                    - Pointer to the RSDP
243  *
244  * RETURN:      Status
245  *
246  * DESCRIPTION: This function is called to parse the Root System Description
247  *              Table (RSDT or XSDT)
248  *
249  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
250  *              be mapped and cannot be copied because it contains the actual
251  *              memory location of the ACPI Global Lock.
252  *
253  ******************************************************************************/
254 
255 acpi_status ACPI_INIT_FUNCTION
256 acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
257 {
258 	struct acpi_table_rsdp *rsdp;
259 	u32 table_entry_size;
260 	u32 i;
261 	u32 table_count;
262 	struct acpi_table_header *table;
263 	acpi_physical_address address;
264 	u32 length;
265 	u8 *table_entry;
266 	acpi_status status;
267 	u32 table_index;
268 
269 	ACPI_FUNCTION_TRACE(tb_parse_root_table);
270 
271 	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
272 
273 	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
274 	if (!rsdp) {
275 		return_ACPI_STATUS(AE_NO_MEMORY);
276 	}
277 
278 	acpi_tb_print_table_header(rsdp_address,
279 				   ACPI_CAST_PTR(struct acpi_table_header,
280 						 rsdp));
281 
282 	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
283 
284 	if ((rsdp->revision > 1) &&
285 	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
286 		/*
287 		 * RSDP contains an XSDT (64-bit physical addresses). We must use
288 		 * the XSDT if the revision is > 1 and the XSDT pointer is present,
289 		 * as per the ACPI specification.
290 		 */
291 		address = (acpi_physical_address)rsdp->xsdt_physical_address;
292 		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
293 	} else {
294 		/* Root table is an RSDT (32-bit physical addresses) */
295 
296 		address = (acpi_physical_address)rsdp->rsdt_physical_address;
297 		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
298 	}
299 
300 	/*
301 	 * It is not possible to map more than one entry in some environments,
302 	 * so unmap the RSDP here before mapping other tables
303 	 */
304 	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
305 
306 	/* Map the RSDT/XSDT table header to get the full table length */
307 
308 	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
309 	if (!table) {
310 		return_ACPI_STATUS(AE_NO_MEMORY);
311 	}
312 
313 	acpi_tb_print_table_header(address, table);
314 
315 	/*
316 	 * Validate length of the table, and map entire table.
317 	 * Minimum length table must contain at least one entry.
318 	 */
319 	length = table->length;
320 	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
321 
322 	if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
323 		ACPI_BIOS_ERROR((AE_INFO,
324 				 "Invalid table length 0x%X in RSDT/XSDT",
325 				 length));
326 		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
327 	}
328 
329 	table = acpi_os_map_memory(address, length);
330 	if (!table) {
331 		return_ACPI_STATUS(AE_NO_MEMORY);
332 	}
333 
334 	/* Validate the root table checksum */
335 
336 	status = acpi_tb_verify_checksum(table, length);
337 	if (ACPI_FAILURE(status)) {
338 		acpi_os_unmap_memory(table, length);
339 		return_ACPI_STATUS(status);
340 	}
341 
342 	/* Get the number of entries and pointer to first entry */
343 
344 	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
345 			    table_entry_size);
346 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
347 
348 	/* Initialize the root table array from the RSDT/XSDT */
349 
350 	for (i = 0; i < table_count; i++) {
351 
352 		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
353 
354 		address =
355 		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
356 
357 		/* Skip NULL entries in RSDT/XSDT */
358 
359 		if (!address) {
360 			goto next_table;
361 		}
362 
363 		status = acpi_tb_install_standard_table(address,
364 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
365 							FALSE, TRUE,
366 							&table_index);
367 
368 		if (ACPI_SUCCESS(status) &&
369 		    ACPI_COMPARE_NAME(&acpi_gbl_root_table_list.
370 				      tables[table_index].signature,
371 				      ACPI_SIG_FADT)) {
372 			acpi_gbl_fadt_index = table_index;
373 			acpi_tb_parse_fadt();
374 		}
375 
376 next_table:
377 
378 		table_entry += table_entry_size;
379 	}
380 
381 	acpi_os_unmap_memory(table, length);
382 	return_ACPI_STATUS(AE_OK);
383 }
384 
385 /*******************************************************************************
386  *
387  * FUNCTION:    acpi_tb_get_table
388  *
389  * PARAMETERS:  table_desc          - Table descriptor
390  *              out_table           - Where the pointer to the table is returned
391  *
392  * RETURN:      Status and pointer to the requested table
393  *
394  * DESCRIPTION: Increase a reference to a table descriptor and return the
395  *              validated table pointer.
396  *              If the table descriptor is an entry of the root table list,
397  *              this API must be invoked with ACPI_MTX_TABLES acquired.
398  *
399  ******************************************************************************/
400 
401 acpi_status
402 acpi_tb_get_table(struct acpi_table_desc *table_desc,
403 		  struct acpi_table_header **out_table)
404 {
405 	acpi_status status;
406 
407 	ACPI_FUNCTION_TRACE(acpi_tb_get_table);
408 
409 	if (table_desc->validation_count == 0) {
410 
411 		/* Table need to be "VALIDATED" */
412 
413 		status = acpi_tb_validate_table(table_desc);
414 		if (ACPI_FAILURE(status)) {
415 			return_ACPI_STATUS(status);
416 		}
417 	}
418 
419 	table_desc->validation_count++;
420 	if (table_desc->validation_count == 0) {
421 		ACPI_ERROR((AE_INFO,
422 			    "Table %p, Validation count is zero after increment\n",
423 			    table_desc));
424 		table_desc->validation_count--;
425 		return_ACPI_STATUS(AE_LIMIT);
426 	}
427 
428 	*out_table = table_desc->pointer;
429 	return_ACPI_STATUS(AE_OK);
430 }
431 
432 /*******************************************************************************
433  *
434  * FUNCTION:    acpi_tb_put_table
435  *
436  * PARAMETERS:  table_desc          - Table descriptor
437  *
438  * RETURN:      None
439  *
440  * DESCRIPTION: Decrease a reference to a table descriptor and release the
441  *              validated table pointer if no references.
442  *              If the table descriptor is an entry of the root table list,
443  *              this API must be invoked with ACPI_MTX_TABLES acquired.
444  *
445  ******************************************************************************/
446 
447 void acpi_tb_put_table(struct acpi_table_desc *table_desc)
448 {
449 
450 	ACPI_FUNCTION_TRACE(acpi_tb_put_table);
451 
452 	if (table_desc->validation_count == 0) {
453 		ACPI_WARNING((AE_INFO,
454 			      "Table %p, Validation count is zero before decrement\n",
455 			      table_desc));
456 		return_VOID;
457 	}
458 	table_desc->validation_count--;
459 
460 	if (table_desc->validation_count == 0) {
461 
462 		/* Table need to be "INVALIDATED" */
463 
464 		acpi_tb_invalidate_table(table_desc);
465 	}
466 
467 	return_VOID;
468 }
469