xref: /openbmc/linux/drivers/acpi/apei/apei-base.c (revision 02b4e275)
1 /*
2  * apei-base.c - ACPI Platform Error Interface (APEI) supporting
3  * infrastructure
4  *
5  * APEI allows to report errors (for example from the chipset) to the
6  * the operating system. This improves NMI handling especially. In
7  * addition it supports error serialization and error injection.
8  *
9  * For more information about APEI, please refer to ACPI Specification
10  * version 4.0, chapter 17.
11  *
12  * This file has Common functions used by more than one APEI table,
13  * including framework of interpreter for ERST and EINJ; resource
14  * management for APEI registers.
15  *
16  * Copyright (C) 2009, Intel Corp.
17  *	Author: Huang Ying <ying.huang@intel.com>
18  *
19  * This program is free software; you can redistribute it and/or
20  * modify it under the terms of the GNU General Public License version
21  * 2 as published by the Free Software Foundation.
22  *
23  * This program is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
26  * GNU General Public License for more details.
27  *
28  * You should have received a copy of the GNU General Public License
29  * along with this program; if not, write to the Free Software
30  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
31  */
32 
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/acpi.h>
37 #include <linux/slab.h>
38 #include <linux/io.h>
39 #include <linux/kref.h>
40 #include <linux/rculist.h>
41 #include <linux/interrupt.h>
42 #include <linux/debugfs.h>
43 #include <asm/unaligned.h>
44 
45 #include "apei-internal.h"
46 
47 #define APEI_PFX "APEI: "
48 
49 /*
50  * APEI ERST (Error Record Serialization Table) and EINJ (Error
51  * INJection) interpreter framework.
52  */
53 
54 #define APEI_EXEC_PRESERVE_REGISTER	0x1
55 
56 void apei_exec_ctx_init(struct apei_exec_context *ctx,
57 			struct apei_exec_ins_type *ins_table,
58 			u32 instructions,
59 			struct acpi_whea_header *action_table,
60 			u32 entries)
61 {
62 	ctx->ins_table = ins_table;
63 	ctx->instructions = instructions;
64 	ctx->action_table = action_table;
65 	ctx->entries = entries;
66 }
67 EXPORT_SYMBOL_GPL(apei_exec_ctx_init);
68 
69 int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val)
70 {
71 	int rc;
72 
73 	rc = apei_read(val, &entry->register_region);
74 	if (rc)
75 		return rc;
76 	*val >>= entry->register_region.bit_offset;
77 	*val &= entry->mask;
78 
79 	return 0;
80 }
81 
82 int apei_exec_read_register(struct apei_exec_context *ctx,
83 			    struct acpi_whea_header *entry)
84 {
85 	int rc;
86 	u64 val = 0;
87 
88 	rc = __apei_exec_read_register(entry, &val);
89 	if (rc)
90 		return rc;
91 	ctx->value = val;
92 
93 	return 0;
94 }
95 EXPORT_SYMBOL_GPL(apei_exec_read_register);
96 
97 int apei_exec_read_register_value(struct apei_exec_context *ctx,
98 				  struct acpi_whea_header *entry)
99 {
100 	int rc;
101 
102 	rc = apei_exec_read_register(ctx, entry);
103 	if (rc)
104 		return rc;
105 	ctx->value = (ctx->value == entry->value);
106 
107 	return 0;
108 }
109 EXPORT_SYMBOL_GPL(apei_exec_read_register_value);
110 
111 int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val)
112 {
113 	int rc;
114 
115 	val &= entry->mask;
116 	val <<= entry->register_region.bit_offset;
117 	if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) {
118 		u64 valr = 0;
119 		rc = apei_read(&valr, &entry->register_region);
120 		if (rc)
121 			return rc;
122 		valr &= ~(entry->mask << entry->register_region.bit_offset);
123 		val |= valr;
124 	}
125 	rc = apei_write(val, &entry->register_region);
126 
127 	return rc;
128 }
129 
130 int apei_exec_write_register(struct apei_exec_context *ctx,
131 			     struct acpi_whea_header *entry)
132 {
133 	return __apei_exec_write_register(entry, ctx->value);
134 }
135 EXPORT_SYMBOL_GPL(apei_exec_write_register);
136 
137 int apei_exec_write_register_value(struct apei_exec_context *ctx,
138 				   struct acpi_whea_header *entry)
139 {
140 	int rc;
141 
142 	ctx->value = entry->value;
143 	rc = apei_exec_write_register(ctx, entry);
144 
145 	return rc;
146 }
147 EXPORT_SYMBOL_GPL(apei_exec_write_register_value);
148 
149 int apei_exec_noop(struct apei_exec_context *ctx,
150 		   struct acpi_whea_header *entry)
151 {
152 	return 0;
153 }
154 EXPORT_SYMBOL_GPL(apei_exec_noop);
155 
156 /*
157  * Interpret the specified action. Go through whole action table,
158  * execute all instructions belong to the action.
159  */
160 int __apei_exec_run(struct apei_exec_context *ctx, u8 action,
161 		    bool optional)
162 {
163 	int rc = -ENOENT;
164 	u32 i, ip;
165 	struct acpi_whea_header *entry;
166 	apei_exec_ins_func_t run;
167 
168 	ctx->ip = 0;
169 
170 	/*
171 	 * "ip" is the instruction pointer of current instruction,
172 	 * "ctx->ip" specifies the next instruction to executed,
173 	 * instruction "run" function may change the "ctx->ip" to
174 	 * implement "goto" semantics.
175 	 */
176 rewind:
177 	ip = 0;
178 	for (i = 0; i < ctx->entries; i++) {
179 		entry = &ctx->action_table[i];
180 		if (entry->action != action)
181 			continue;
182 		if (ip == ctx->ip) {
183 			if (entry->instruction >= ctx->instructions ||
184 			    !ctx->ins_table[entry->instruction].run) {
185 				pr_warning(FW_WARN APEI_PFX
186 			"Invalid action table, unknown instruction type: %d\n",
187 					   entry->instruction);
188 				return -EINVAL;
189 			}
190 			run = ctx->ins_table[entry->instruction].run;
191 			rc = run(ctx, entry);
192 			if (rc < 0)
193 				return rc;
194 			else if (rc != APEI_EXEC_SET_IP)
195 				ctx->ip++;
196 		}
197 		ip++;
198 		if (ctx->ip < ip)
199 			goto rewind;
200 	}
201 
202 	return !optional && rc < 0 ? rc : 0;
203 }
204 EXPORT_SYMBOL_GPL(__apei_exec_run);
205 
206 typedef int (*apei_exec_entry_func_t)(struct apei_exec_context *ctx,
207 				      struct acpi_whea_header *entry,
208 				      void *data);
209 
210 static int apei_exec_for_each_entry(struct apei_exec_context *ctx,
211 				    apei_exec_entry_func_t func,
212 				    void *data,
213 				    int *end)
214 {
215 	u8 ins;
216 	int i, rc;
217 	struct acpi_whea_header *entry;
218 	struct apei_exec_ins_type *ins_table = ctx->ins_table;
219 
220 	for (i = 0; i < ctx->entries; i++) {
221 		entry = ctx->action_table + i;
222 		ins = entry->instruction;
223 		if (end)
224 			*end = i;
225 		if (ins >= ctx->instructions || !ins_table[ins].run) {
226 			pr_warning(FW_WARN APEI_PFX
227 			"Invalid action table, unknown instruction type: %d\n",
228 				   ins);
229 			return -EINVAL;
230 		}
231 		rc = func(ctx, entry, data);
232 		if (rc)
233 			return rc;
234 	}
235 
236 	return 0;
237 }
238 
239 static int pre_map_gar_callback(struct apei_exec_context *ctx,
240 				struct acpi_whea_header *entry,
241 				void *data)
242 {
243 	u8 ins = entry->instruction;
244 
245 	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
246 		return apei_map_generic_address(&entry->register_region);
247 
248 	return 0;
249 }
250 
251 /*
252  * Pre-map all GARs in action table to make it possible to access them
253  * in NMI handler.
254  */
255 int apei_exec_pre_map_gars(struct apei_exec_context *ctx)
256 {
257 	int rc, end;
258 
259 	rc = apei_exec_for_each_entry(ctx, pre_map_gar_callback,
260 				      NULL, &end);
261 	if (rc) {
262 		struct apei_exec_context ctx_unmap;
263 		memcpy(&ctx_unmap, ctx, sizeof(*ctx));
264 		ctx_unmap.entries = end;
265 		apei_exec_post_unmap_gars(&ctx_unmap);
266 	}
267 
268 	return rc;
269 }
270 EXPORT_SYMBOL_GPL(apei_exec_pre_map_gars);
271 
272 static int post_unmap_gar_callback(struct apei_exec_context *ctx,
273 				   struct acpi_whea_header *entry,
274 				   void *data)
275 {
276 	u8 ins = entry->instruction;
277 
278 	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
279 		apei_unmap_generic_address(&entry->register_region);
280 
281 	return 0;
282 }
283 
284 /* Post-unmap all GAR in action table. */
285 int apei_exec_post_unmap_gars(struct apei_exec_context *ctx)
286 {
287 	return apei_exec_for_each_entry(ctx, post_unmap_gar_callback,
288 					NULL, NULL);
289 }
290 EXPORT_SYMBOL_GPL(apei_exec_post_unmap_gars);
291 
292 /*
293  * Resource management for GARs in APEI
294  */
295 struct apei_res {
296 	struct list_head list;
297 	unsigned long start;
298 	unsigned long end;
299 };
300 
301 /* Collect all resources requested, to avoid conflict */
302 struct apei_resources apei_resources_all = {
303 	.iomem = LIST_HEAD_INIT(apei_resources_all.iomem),
304 	.ioport = LIST_HEAD_INIT(apei_resources_all.ioport),
305 };
306 
307 static int apei_res_add(struct list_head *res_list,
308 			unsigned long start, unsigned long size)
309 {
310 	struct apei_res *res, *resn, *res_ins = NULL;
311 	unsigned long end = start + size;
312 
313 	if (end <= start)
314 		return 0;
315 repeat:
316 	list_for_each_entry_safe(res, resn, res_list, list) {
317 		if (res->start > end || res->end < start)
318 			continue;
319 		else if (end <= res->end && start >= res->start) {
320 			kfree(res_ins);
321 			return 0;
322 		}
323 		list_del(&res->list);
324 		res->start = start = min(res->start, start);
325 		res->end = end = max(res->end, end);
326 		kfree(res_ins);
327 		res_ins = res;
328 		goto repeat;
329 	}
330 
331 	if (res_ins)
332 		list_add(&res_ins->list, res_list);
333 	else {
334 		res_ins = kmalloc(sizeof(*res), GFP_KERNEL);
335 		if (!res_ins)
336 			return -ENOMEM;
337 		res_ins->start = start;
338 		res_ins->end = end;
339 		list_add(&res_ins->list, res_list);
340 	}
341 
342 	return 0;
343 }
344 
345 static int apei_res_sub(struct list_head *res_list1,
346 			struct list_head *res_list2)
347 {
348 	struct apei_res *res1, *resn1, *res2, *res;
349 	res1 = list_entry(res_list1->next, struct apei_res, list);
350 	resn1 = list_entry(res1->list.next, struct apei_res, list);
351 	while (&res1->list != res_list1) {
352 		list_for_each_entry(res2, res_list2, list) {
353 			if (res1->start >= res2->end ||
354 			    res1->end <= res2->start)
355 				continue;
356 			else if (res1->end <= res2->end &&
357 				 res1->start >= res2->start) {
358 				list_del(&res1->list);
359 				kfree(res1);
360 				break;
361 			} else if (res1->end > res2->end &&
362 				   res1->start < res2->start) {
363 				res = kmalloc(sizeof(*res), GFP_KERNEL);
364 				if (!res)
365 					return -ENOMEM;
366 				res->start = res2->end;
367 				res->end = res1->end;
368 				res1->end = res2->start;
369 				list_add(&res->list, &res1->list);
370 				resn1 = res;
371 			} else {
372 				if (res1->start < res2->start)
373 					res1->end = res2->start;
374 				else
375 					res1->start = res2->end;
376 			}
377 		}
378 		res1 = resn1;
379 		resn1 = list_entry(resn1->list.next, struct apei_res, list);
380 	}
381 
382 	return 0;
383 }
384 
385 static void apei_res_clean(struct list_head *res_list)
386 {
387 	struct apei_res *res, *resn;
388 
389 	list_for_each_entry_safe(res, resn, res_list, list) {
390 		list_del(&res->list);
391 		kfree(res);
392 	}
393 }
394 
395 void apei_resources_fini(struct apei_resources *resources)
396 {
397 	apei_res_clean(&resources->iomem);
398 	apei_res_clean(&resources->ioport);
399 }
400 EXPORT_SYMBOL_GPL(apei_resources_fini);
401 
402 static int apei_resources_merge(struct apei_resources *resources1,
403 				struct apei_resources *resources2)
404 {
405 	int rc;
406 	struct apei_res *res;
407 
408 	list_for_each_entry(res, &resources2->iomem, list) {
409 		rc = apei_res_add(&resources1->iomem, res->start,
410 				  res->end - res->start);
411 		if (rc)
412 			return rc;
413 	}
414 	list_for_each_entry(res, &resources2->ioport, list) {
415 		rc = apei_res_add(&resources1->ioport, res->start,
416 				  res->end - res->start);
417 		if (rc)
418 			return rc;
419 	}
420 
421 	return 0;
422 }
423 
424 int apei_resources_add(struct apei_resources *resources,
425 		       unsigned long start, unsigned long size,
426 		       bool iomem)
427 {
428 	if (iomem)
429 		return apei_res_add(&resources->iomem, start, size);
430 	else
431 		return apei_res_add(&resources->ioport, start, size);
432 }
433 EXPORT_SYMBOL_GPL(apei_resources_add);
434 
435 /*
436  * EINJ has two groups of GARs (EINJ table entry and trigger table
437  * entry), so common resources are subtracted from the trigger table
438  * resources before the second requesting.
439  */
440 int apei_resources_sub(struct apei_resources *resources1,
441 		       struct apei_resources *resources2)
442 {
443 	int rc;
444 
445 	rc = apei_res_sub(&resources1->iomem, &resources2->iomem);
446 	if (rc)
447 		return rc;
448 	return apei_res_sub(&resources1->ioport, &resources2->ioport);
449 }
450 EXPORT_SYMBOL_GPL(apei_resources_sub);
451 
452 static int apei_get_res_callback(__u64 start, __u64 size, void *data)
453 {
454 	struct apei_resources *resources = data;
455 	return apei_res_add(&resources->iomem, start, size);
456 }
457 
458 static int apei_get_nvs_resources(struct apei_resources *resources)
459 {
460 	return acpi_nvs_for_each_region(apei_get_res_callback, resources);
461 }
462 
463 int (*arch_apei_filter_addr)(int (*func)(__u64 start, __u64 size,
464 				     void *data), void *data);
465 static int apei_get_arch_resources(struct apei_resources *resources)
466 
467 {
468 	return arch_apei_filter_addr(apei_get_res_callback, resources);
469 }
470 
471 /*
472  * IO memory/port resource management mechanism is used to check
473  * whether memory/port area used by GARs conflicts with normal memory
474  * or IO memory/port of devices.
475  */
476 int apei_resources_request(struct apei_resources *resources,
477 			   const char *desc)
478 {
479 	struct apei_res *res, *res_bak = NULL;
480 	struct resource *r;
481 	struct apei_resources nvs_resources, arch_res;
482 	int rc;
483 
484 	rc = apei_resources_sub(resources, &apei_resources_all);
485 	if (rc)
486 		return rc;
487 
488 	/*
489 	 * Some firmware uses ACPI NVS region, that has been marked as
490 	 * busy, so exclude it from APEI resources to avoid false
491 	 * conflict.
492 	 */
493 	apei_resources_init(&nvs_resources);
494 	rc = apei_get_nvs_resources(&nvs_resources);
495 	if (rc)
496 		goto nvs_res_fini;
497 	rc = apei_resources_sub(resources, &nvs_resources);
498 	if (rc)
499 		goto nvs_res_fini;
500 
501 	if (arch_apei_filter_addr) {
502 		apei_resources_init(&arch_res);
503 		rc = apei_get_arch_resources(&arch_res);
504 		if (rc)
505 			goto arch_res_fini;
506 		rc = apei_resources_sub(resources, &arch_res);
507 		if (rc)
508 			goto arch_res_fini;
509 	}
510 
511 	rc = -EINVAL;
512 	list_for_each_entry(res, &resources->iomem, list) {
513 		r = request_mem_region(res->start, res->end - res->start,
514 				       desc);
515 		if (!r) {
516 			pr_err(APEI_PFX
517 		"Can not request [mem %#010llx-%#010llx] for %s registers\n",
518 			       (unsigned long long)res->start,
519 			       (unsigned long long)res->end - 1, desc);
520 			res_bak = res;
521 			goto err_unmap_iomem;
522 		}
523 	}
524 
525 	list_for_each_entry(res, &resources->ioport, list) {
526 		r = request_region(res->start, res->end - res->start, desc);
527 		if (!r) {
528 			pr_err(APEI_PFX
529 		"Can not request [io  %#06llx-%#06llx] for %s registers\n",
530 			       (unsigned long long)res->start,
531 			       (unsigned long long)res->end - 1, desc);
532 			res_bak = res;
533 			goto err_unmap_ioport;
534 		}
535 	}
536 
537 	rc = apei_resources_merge(&apei_resources_all, resources);
538 	if (rc) {
539 		pr_err(APEI_PFX "Fail to merge resources!\n");
540 		goto err_unmap_ioport;
541 	}
542 
543 	return 0;
544 err_unmap_ioport:
545 	list_for_each_entry(res, &resources->ioport, list) {
546 		if (res == res_bak)
547 			break;
548 		release_region(res->start, res->end - res->start);
549 	}
550 	res_bak = NULL;
551 err_unmap_iomem:
552 	list_for_each_entry(res, &resources->iomem, list) {
553 		if (res == res_bak)
554 			break;
555 		release_mem_region(res->start, res->end - res->start);
556 	}
557 arch_res_fini:
558 	apei_resources_fini(&arch_res);
559 nvs_res_fini:
560 	apei_resources_fini(&nvs_resources);
561 	return rc;
562 }
563 EXPORT_SYMBOL_GPL(apei_resources_request);
564 
565 void apei_resources_release(struct apei_resources *resources)
566 {
567 	int rc;
568 	struct apei_res *res;
569 
570 	list_for_each_entry(res, &resources->iomem, list)
571 		release_mem_region(res->start, res->end - res->start);
572 	list_for_each_entry(res, &resources->ioport, list)
573 		release_region(res->start, res->end - res->start);
574 
575 	rc = apei_resources_sub(&apei_resources_all, resources);
576 	if (rc)
577 		pr_err(APEI_PFX "Fail to sub resources!\n");
578 }
579 EXPORT_SYMBOL_GPL(apei_resources_release);
580 
581 static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr,
582 				u32 *access_bit_width)
583 {
584 	u32 bit_width, bit_offset, access_size_code, space_id;
585 
586 	bit_width = reg->bit_width;
587 	bit_offset = reg->bit_offset;
588 	access_size_code = reg->access_width;
589 	space_id = reg->space_id;
590 	*paddr = get_unaligned(&reg->address);
591 	if (!*paddr) {
592 		pr_warning(FW_BUG APEI_PFX
593 			   "Invalid physical address in GAR [0x%llx/%u/%u/%u/%u]\n",
594 			   *paddr, bit_width, bit_offset, access_size_code,
595 			   space_id);
596 		return -EINVAL;
597 	}
598 
599 	if (access_size_code < 1 || access_size_code > 4) {
600 		pr_warning(FW_BUG APEI_PFX
601 			   "Invalid access size code in GAR [0x%llx/%u/%u/%u/%u]\n",
602 			   *paddr, bit_width, bit_offset, access_size_code,
603 			   space_id);
604 		return -EINVAL;
605 	}
606 	*access_bit_width = 1UL << (access_size_code + 2);
607 
608 	/* Fixup common BIOS bug */
609 	if (bit_width == 32 && bit_offset == 0 && (*paddr & 0x03) == 0 &&
610 	    *access_bit_width < 32)
611 		*access_bit_width = 32;
612 	else if (bit_width == 64 && bit_offset == 0 && (*paddr & 0x07) == 0 &&
613 	    *access_bit_width < 64)
614 		*access_bit_width = 64;
615 
616 	if ((bit_width + bit_offset) > *access_bit_width) {
617 		pr_warning(FW_BUG APEI_PFX
618 			   "Invalid bit width + offset in GAR [0x%llx/%u/%u/%u/%u]\n",
619 			   *paddr, bit_width, bit_offset, access_size_code,
620 			   space_id);
621 		return -EINVAL;
622 	}
623 
624 	if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
625 	    space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
626 		pr_warning(FW_BUG APEI_PFX
627 			   "Invalid address space type in GAR [0x%llx/%u/%u/%u/%u]\n",
628 			   *paddr, bit_width, bit_offset, access_size_code,
629 			   space_id);
630 		return -EINVAL;
631 	}
632 
633 	return 0;
634 }
635 
636 int apei_map_generic_address(struct acpi_generic_address *reg)
637 {
638 	int rc;
639 	u32 access_bit_width;
640 	u64 address;
641 
642 	rc = apei_check_gar(reg, &address, &access_bit_width);
643 	if (rc)
644 		return rc;
645 	return acpi_os_map_generic_address(reg);
646 }
647 EXPORT_SYMBOL_GPL(apei_map_generic_address);
648 
649 /* read GAR in interrupt (including NMI) or process context */
650 int apei_read(u64 *val, struct acpi_generic_address *reg)
651 {
652 	int rc;
653 	u32 access_bit_width;
654 	u64 address;
655 	acpi_status status;
656 
657 	rc = apei_check_gar(reg, &address, &access_bit_width);
658 	if (rc)
659 		return rc;
660 
661 	*val = 0;
662 	switch(reg->space_id) {
663 	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
664 		status = acpi_os_read_memory((acpi_physical_address) address,
665 					       val, access_bit_width);
666 		if (ACPI_FAILURE(status))
667 			return -EIO;
668 		break;
669 	case ACPI_ADR_SPACE_SYSTEM_IO:
670 		status = acpi_os_read_port(address, (u32 *)val,
671 					   access_bit_width);
672 		if (ACPI_FAILURE(status))
673 			return -EIO;
674 		break;
675 	default:
676 		return -EINVAL;
677 	}
678 
679 	return 0;
680 }
681 EXPORT_SYMBOL_GPL(apei_read);
682 
683 /* write GAR in interrupt (including NMI) or process context */
684 int apei_write(u64 val, struct acpi_generic_address *reg)
685 {
686 	int rc;
687 	u32 access_bit_width;
688 	u64 address;
689 	acpi_status status;
690 
691 	rc = apei_check_gar(reg, &address, &access_bit_width);
692 	if (rc)
693 		return rc;
694 
695 	switch (reg->space_id) {
696 	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
697 		status = acpi_os_write_memory((acpi_physical_address) address,
698 						val, access_bit_width);
699 		if (ACPI_FAILURE(status))
700 			return -EIO;
701 		break;
702 	case ACPI_ADR_SPACE_SYSTEM_IO:
703 		status = acpi_os_write_port(address, val, access_bit_width);
704 		if (ACPI_FAILURE(status))
705 			return -EIO;
706 		break;
707 	default:
708 		return -EINVAL;
709 	}
710 
711 	return 0;
712 }
713 EXPORT_SYMBOL_GPL(apei_write);
714 
715 static int collect_res_callback(struct apei_exec_context *ctx,
716 				struct acpi_whea_header *entry,
717 				void *data)
718 {
719 	struct apei_resources *resources = data;
720 	struct acpi_generic_address *reg = &entry->register_region;
721 	u8 ins = entry->instruction;
722 	u32 access_bit_width;
723 	u64 paddr;
724 	int rc;
725 
726 	if (!(ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER))
727 		return 0;
728 
729 	rc = apei_check_gar(reg, &paddr, &access_bit_width);
730 	if (rc)
731 		return rc;
732 
733 	switch (reg->space_id) {
734 	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
735 		return apei_res_add(&resources->iomem, paddr,
736 				    access_bit_width / 8);
737 	case ACPI_ADR_SPACE_SYSTEM_IO:
738 		return apei_res_add(&resources->ioport, paddr,
739 				    access_bit_width / 8);
740 	default:
741 		return -EINVAL;
742 	}
743 }
744 
745 /*
746  * Same register may be used by multiple instructions in GARs, so
747  * resources are collected before requesting.
748  */
749 int apei_exec_collect_resources(struct apei_exec_context *ctx,
750 				struct apei_resources *resources)
751 {
752 	return apei_exec_for_each_entry(ctx, collect_res_callback,
753 					resources, NULL);
754 }
755 EXPORT_SYMBOL_GPL(apei_exec_collect_resources);
756 
757 struct dentry *apei_get_debugfs_dir(void)
758 {
759 	static struct dentry *dapei;
760 
761 	if (!dapei)
762 		dapei = debugfs_create_dir("apei", NULL);
763 
764 	return dapei;
765 }
766 EXPORT_SYMBOL_GPL(apei_get_debugfs_dir);
767 
768 int __weak arch_apei_enable_cmcff(struct acpi_hest_header *hest_hdr,
769 				  void *data)
770 {
771 	return 1;
772 }
773 EXPORT_SYMBOL_GPL(arch_apei_enable_cmcff);
774 
775 void __weak arch_apei_report_mem_error(int sev,
776 				       struct cper_sec_mem_err *mem_err)
777 {
778 }
779 EXPORT_SYMBOL_GPL(arch_apei_report_mem_error);
780 
781 int apei_osc_setup(void)
782 {
783 	static u8 whea_uuid_str[] = "ed855e0c-6c90-47bf-a62a-26de0fc5ad5c";
784 	acpi_handle handle;
785 	u32 capbuf[3];
786 	struct acpi_osc_context context = {
787 		.uuid_str	= whea_uuid_str,
788 		.rev		= 1,
789 		.cap.length	= sizeof(capbuf),
790 		.cap.pointer	= capbuf,
791 	};
792 
793 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
794 	capbuf[OSC_SUPPORT_DWORD] = 1;
795 	capbuf[OSC_CONTROL_DWORD] = 0;
796 
797 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle))
798 	    || ACPI_FAILURE(acpi_run_osc(handle, &context)))
799 		return -EIO;
800 	else {
801 		kfree(context.ret.pointer);
802 		return 0;
803 	}
804 }
805 EXPORT_SYMBOL_GPL(apei_osc_setup);
806