Merge tag 'tty-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
[cascardo/linux.git] / drivers / acpi / acpica / tbinstal.c
1 /******************************************************************************
2  *
3  * Module Name: tbinstal - ACPI table installation and removal
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2016, 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("tbinstal")
50
51 /* Local prototypes */
52 static u8
53 acpi_tb_compare_tables(struct acpi_table_desc *table_desc, u32 table_index);
54
55 /*******************************************************************************
56  *
57  * FUNCTION:    acpi_tb_compare_tables
58  *
59  * PARAMETERS:  table_desc          - Table 1 descriptor to be compared
60  *              table_index         - Index of table 2 to be compared
61  *
62  * RETURN:      TRUE if both tables are identical.
63  *
64  * DESCRIPTION: This function compares a table with another table that has
65  *              already been installed in the root table list.
66  *
67  ******************************************************************************/
68
69 static u8
70 acpi_tb_compare_tables(struct acpi_table_desc *table_desc, u32 table_index)
71 {
72         acpi_status status = AE_OK;
73         u8 is_identical;
74         struct acpi_table_header *table;
75         u32 table_length;
76         u8 table_flags;
77
78         status =
79             acpi_tb_acquire_table(&acpi_gbl_root_table_list.tables[table_index],
80                                   &table, &table_length, &table_flags);
81         if (ACPI_FAILURE(status)) {
82                 return (FALSE);
83         }
84
85         /*
86          * Check for a table match on the entire table length,
87          * not just the header.
88          */
89         is_identical = (u8)((table_desc->length != table_length ||
90                              memcmp(table_desc->pointer, table, table_length)) ?
91                             FALSE : TRUE);
92
93         /* Release the acquired table */
94
95         acpi_tb_release_table(table, table_length, table_flags);
96         return (is_identical);
97 }
98
99 /*******************************************************************************
100  *
101  * FUNCTION:    acpi_tb_install_table_with_override
102  *
103  * PARAMETERS:  new_table_desc          - New table descriptor to install
104  *              override                - Whether override should be performed
105  *              table_index             - Where the table index is returned
106  *
107  * RETURN:      None
108  *
109  * DESCRIPTION: Install an ACPI table into the global data structure. The
110  *              table override mechanism is called to allow the host
111  *              OS to replace any table before it is installed in the root
112  *              table array.
113  *
114  ******************************************************************************/
115
116 void
117 acpi_tb_install_table_with_override(struct acpi_table_desc *new_table_desc,
118                                     u8 override, u32 *table_index)
119 {
120         u32 i;
121         acpi_status status;
122
123         status = acpi_tb_get_next_table_descriptor(&i, NULL);
124         if (ACPI_FAILURE(status)) {
125                 return;
126         }
127
128         /*
129          * ACPI Table Override:
130          *
131          * Before we install the table, let the host OS override it with a new
132          * one if desired. Any table within the RSDT/XSDT can be replaced,
133          * including the DSDT which is pointed to by the FADT.
134          */
135         if (override) {
136                 acpi_tb_override_table(new_table_desc);
137         }
138
139         acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.tables[i],
140                                       new_table_desc->address,
141                                       new_table_desc->flags,
142                                       new_table_desc->pointer);
143
144         acpi_tb_print_table_header(new_table_desc->address,
145                                    new_table_desc->pointer);
146
147         /* This synchronizes acpi_gbl_dsdt_index */
148
149         *table_index = i;
150
151         /* Set the global integer width (based upon revision of the DSDT) */
152
153         if (i == acpi_gbl_dsdt_index) {
154                 acpi_ut_set_integer_width(new_table_desc->pointer->revision);
155         }
156 }
157
158 /*******************************************************************************
159  *
160  * FUNCTION:    acpi_tb_install_standard_table
161  *
162  * PARAMETERS:  address             - Address of the table (might be a virtual
163  *                                    address depending on the table_flags)
164  *              flags               - Flags for the table
165  *              reload              - Whether reload should be performed
166  *              override            - Whether override should be performed
167  *              table_index         - Where the table index is returned
168  *
169  * RETURN:      Status
170  *
171  * DESCRIPTION: This function is called to verify and install an ACPI table.
172  *              When this function is called by "Load" or "LoadTable" opcodes,
173  *              or by acpi_load_table() API, the "Reload" parameter is set.
174  *              After sucessfully returning from this function, table is
175  *              "INSTALLED" but not "VALIDATED".
176  *
177  ******************************************************************************/
178
179 acpi_status
180 acpi_tb_install_standard_table(acpi_physical_address address,
181                                u8 flags,
182                                u8 reload, u8 override, u32 *table_index)
183 {
184         u32 i;
185         acpi_status status = AE_OK;
186         struct acpi_table_desc new_table_desc;
187
188         ACPI_FUNCTION_TRACE(tb_install_standard_table);
189
190         /* Acquire a temporary table descriptor for validation */
191
192         status = acpi_tb_acquire_temp_table(&new_table_desc, address, flags);
193         if (ACPI_FAILURE(status)) {
194                 ACPI_ERROR((AE_INFO,
195                             "Could not acquire table length at %8.8X%8.8X",
196                             ACPI_FORMAT_UINT64(address)));
197                 return_ACPI_STATUS(status);
198         }
199
200         /*
201          * Optionally do not load any SSDTs from the RSDT/XSDT. This can
202          * be useful for debugging ACPI problems on some machines.
203          */
204         if (!reload &&
205             acpi_gbl_disable_ssdt_table_install &&
206             ACPI_COMPARE_NAME(&new_table_desc.signature, ACPI_SIG_SSDT)) {
207                 ACPI_INFO(("Ignoring installation of %4.4s at %8.8X%8.8X",
208                            new_table_desc.signature.ascii,
209                            ACPI_FORMAT_UINT64(address)));
210                 goto release_and_exit;
211         }
212
213         /* Validate and verify a table before installation */
214
215         status = acpi_tb_verify_temp_table(&new_table_desc, NULL);
216         if (ACPI_FAILURE(status)) {
217                 goto release_and_exit;
218         }
219
220         if (reload) {
221                 /*
222                  * Validate the incoming table signature.
223                  *
224                  * 1) Originally, we checked the table signature for "SSDT" or "PSDT".
225                  * 2) We added support for OEMx tables, signature "OEM".
226                  * 3) Valid tables were encountered with a null signature, so we just
227                  *    gave up on validating the signature, (05/2008).
228                  * 4) We encountered non-AML tables such as the MADT, which caused
229                  *    interpreter errors and kernel faults. So now, we once again allow
230                  *    only "SSDT", "OEMx", and now, also a null signature. (05/2011).
231                  */
232                 if ((new_table_desc.signature.ascii[0] != 0x00) &&
233                     (!ACPI_COMPARE_NAME
234                      (&new_table_desc.signature, ACPI_SIG_SSDT))
235                     && (strncmp(new_table_desc.signature.ascii, "OEM", 3))) {
236                         ACPI_BIOS_ERROR((AE_INFO,
237                                          "Table has invalid signature [%4.4s] (0x%8.8X), "
238                                          "must be SSDT or OEMx",
239                                          acpi_ut_valid_nameseg(new_table_desc.
240                                                                signature.
241                                                                ascii) ?
242                                          new_table_desc.signature.
243                                          ascii : "????",
244                                          new_table_desc.signature.integer));
245
246                         status = AE_BAD_SIGNATURE;
247                         goto release_and_exit;
248                 }
249
250                 /* Check if table is already registered */
251
252                 for (i = 0; i < acpi_gbl_root_table_list.current_table_count;
253                      ++i) {
254                         /*
255                          * Check for a table match on the entire table length,
256                          * not just the header.
257                          */
258                         if (!acpi_tb_compare_tables(&new_table_desc, i)) {
259                                 continue;
260                         }
261
262                         /*
263                          * Note: the current mechanism does not unregister a table if it is
264                          * dynamically unloaded. The related namespace entries are deleted,
265                          * but the table remains in the root table list.
266                          *
267                          * The assumption here is that the number of different tables that
268                          * will be loaded is actually small, and there is minimal overhead
269                          * in just keeping the table in case it is needed again.
270                          *
271                          * If this assumption changes in the future (perhaps on large
272                          * machines with many table load/unload operations), tables will
273                          * need to be unregistered when they are unloaded, and slots in the
274                          * root table list should be reused when empty.
275                          */
276                         if (acpi_gbl_root_table_list.tables[i].flags &
277                             ACPI_TABLE_IS_LOADED) {
278
279                                 /* Table is still loaded, this is an error */
280
281                                 status = AE_ALREADY_EXISTS;
282                                 goto release_and_exit;
283                         } else {
284                                 /*
285                                  * Table was unloaded, allow it to be reloaded.
286                                  * As we are going to return AE_OK to the caller, we should
287                                  * take the responsibility of freeing the input descriptor.
288                                  * Refill the input descriptor to ensure
289                                  * acpi_tb_install_table_with_override() can be called again to
290                                  * indicate the re-installation.
291                                  */
292                                 acpi_tb_uninstall_table(&new_table_desc);
293                                 *table_index = i;
294                                 return_ACPI_STATUS(AE_OK);
295                         }
296                 }
297         }
298
299         /* Add the table to the global root table list */
300
301         acpi_tb_install_table_with_override(&new_table_desc, override,
302                                             table_index);
303
304         /* Invoke table handler if present */
305
306         if (acpi_gbl_table_handler) {
307                 (void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_INSTALL,
308                                              new_table_desc.pointer,
309                                              acpi_gbl_table_handler_context);
310         }
311
312 release_and_exit:
313
314         /* Release the temporary table descriptor */
315
316         acpi_tb_release_temp_table(&new_table_desc);
317         return_ACPI_STATUS(status);
318 }
319
320 /*******************************************************************************
321  *
322  * FUNCTION:    acpi_tb_override_table
323  *
324  * PARAMETERS:  old_table_desc      - Validated table descriptor to be
325  *                                    overridden
326  *
327  * RETURN:      None
328  *
329  * DESCRIPTION: Attempt table override by calling the OSL override functions.
330  *              Note: If the table is overridden, then the entire new table
331  *              is acquired and returned by this function.
332  *              Before/after invocation, the table descriptor is in a state
333  *              that is "VALIDATED".
334  *
335  ******************************************************************************/
336
337 void acpi_tb_override_table(struct acpi_table_desc *old_table_desc)
338 {
339         acpi_status status;
340         char *override_type;
341         struct acpi_table_desc new_table_desc;
342         struct acpi_table_header *table;
343         acpi_physical_address address;
344         u32 length;
345
346         /* (1) Attempt logical override (returns a logical address) */
347
348         status = acpi_os_table_override(old_table_desc->pointer, &table);
349         if (ACPI_SUCCESS(status) && table) {
350                 acpi_tb_acquire_temp_table(&new_table_desc,
351                                            ACPI_PTR_TO_PHYSADDR(table),
352                                            ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL);
353                 override_type = "Logical";
354                 goto finish_override;
355         }
356
357         /* (2) Attempt physical override (returns a physical address) */
358
359         status = acpi_os_physical_table_override(old_table_desc->pointer,
360                                                  &address, &length);
361         if (ACPI_SUCCESS(status) && address && length) {
362                 acpi_tb_acquire_temp_table(&new_table_desc, address,
363                                            ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL);
364                 override_type = "Physical";
365                 goto finish_override;
366         }
367
368         return;                 /* There was no override */
369
370 finish_override:
371
372         /* Validate and verify a table before overriding */
373
374         status = acpi_tb_verify_temp_table(&new_table_desc, NULL);
375         if (ACPI_FAILURE(status)) {
376                 return;
377         }
378
379         ACPI_INFO(("%4.4s 0x%8.8X%8.8X"
380                    " %s table override, new table: 0x%8.8X%8.8X",
381                    old_table_desc->signature.ascii,
382                    ACPI_FORMAT_UINT64(old_table_desc->address),
383                    override_type, ACPI_FORMAT_UINT64(new_table_desc.address)));
384
385         /* We can now uninstall the original table */
386
387         acpi_tb_uninstall_table(old_table_desc);
388
389         /*
390          * Replace the original table descriptor and keep its state as
391          * "VALIDATED".
392          */
393         acpi_tb_init_table_descriptor(old_table_desc, new_table_desc.address,
394                                       new_table_desc.flags,
395                                       new_table_desc.pointer);
396         acpi_tb_validate_temp_table(old_table_desc);
397
398         /* Release the temporary table descriptor */
399
400         acpi_tb_release_temp_table(&new_table_desc);
401 }
402
403 /*******************************************************************************
404  *
405  * FUNCTION:    acpi_tb_uninstall_table
406  *
407  * PARAMETERS:  table_desc          - Table descriptor
408  *
409  * RETURN:      None
410  *
411  * DESCRIPTION: Delete one internal ACPI table
412  *
413  ******************************************************************************/
414
415 void acpi_tb_uninstall_table(struct acpi_table_desc *table_desc)
416 {
417
418         ACPI_FUNCTION_TRACE(tb_uninstall_table);
419
420         /* Table must be installed */
421
422         if (!table_desc->address) {
423                 return_VOID;
424         }
425
426         acpi_tb_invalidate_table(table_desc);
427
428         if ((table_desc->flags & ACPI_TABLE_ORIGIN_MASK) ==
429             ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL) {
430                 ACPI_FREE(ACPI_PHYSADDR_TO_PTR(table_desc->address));
431         }
432
433         table_desc->address = ACPI_PTR_TO_PHYSADDR(NULL);
434         return_VOID;
435 }