xref: /openbmc/linux/drivers/acpi/apei/ghes.c (revision 3cea11cd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * APEI Generic Hardware Error Source support
4  *
5  * Generic Hardware Error Source provides a way to report platform
6  * hardware errors (such as that from chipset). It works in so called
7  * "Firmware First" mode, that is, hardware errors are reported to
8  * firmware firstly, then reported to Linux by firmware. This way,
9  * some non-standard hardware error registers or non-standard hardware
10  * link can be checked by firmware to produce more hardware error
11  * information for Linux.
12  *
13  * For more information about Generic Hardware Error Source, please
14  * refer to ACPI Specification version 4.0, section 17.3.2.6
15  *
16  * Copyright 2010,2011 Intel Corp.
17  *   Author: Huang Ying <ying.huang@intel.com>
18  */
19 
20 #include <linux/arm_sdei.h>
21 #include <linux/kernel.h>
22 #include <linux/moduleparam.h>
23 #include <linux/init.h>
24 #include <linux/acpi.h>
25 #include <linux/io.h>
26 #include <linux/interrupt.h>
27 #include <linux/timer.h>
28 #include <linux/cper.h>
29 #include <linux/platform_device.h>
30 #include <linux/mutex.h>
31 #include <linux/ratelimit.h>
32 #include <linux/vmalloc.h>
33 #include <linux/irq_work.h>
34 #include <linux/llist.h>
35 #include <linux/genalloc.h>
36 #include <linux/pci.h>
37 #include <linux/pfn.h>
38 #include <linux/aer.h>
39 #include <linux/nmi.h>
40 #include <linux/sched/clock.h>
41 #include <linux/uuid.h>
42 #include <linux/ras.h>
43 #include <linux/task_work.h>
44 
45 #include <acpi/actbl1.h>
46 #include <acpi/ghes.h>
47 #include <acpi/apei.h>
48 #include <asm/fixmap.h>
49 #include <asm/tlbflush.h>
50 #include <ras/ras_event.h>
51 
52 #include "apei-internal.h"
53 
54 #define GHES_PFX	"GHES: "
55 
56 #define GHES_ESTATUS_MAX_SIZE		65536
57 #define GHES_ESOURCE_PREALLOC_MAX_SIZE	65536
58 
59 #define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
60 
61 /* This is just an estimation for memory pool allocation */
62 #define GHES_ESTATUS_CACHE_AVG_SIZE	512
63 
64 #define GHES_ESTATUS_CACHES_SIZE	4
65 
66 #define GHES_ESTATUS_IN_CACHE_MAX_NSEC	10000000000ULL
67 /* Prevent too many caches are allocated because of RCU */
68 #define GHES_ESTATUS_CACHE_ALLOCED_MAX	(GHES_ESTATUS_CACHES_SIZE * 3 / 2)
69 
70 #define GHES_ESTATUS_CACHE_LEN(estatus_len)			\
71 	(sizeof(struct ghes_estatus_cache) + (estatus_len))
72 #define GHES_ESTATUS_FROM_CACHE(estatus_cache)			\
73 	((struct acpi_hest_generic_status *)				\
74 	 ((struct ghes_estatus_cache *)(estatus_cache) + 1))
75 
76 #define GHES_ESTATUS_NODE_LEN(estatus_len)			\
77 	(sizeof(struct ghes_estatus_node) + (estatus_len))
78 #define GHES_ESTATUS_FROM_NODE(estatus_node)			\
79 	((struct acpi_hest_generic_status *)				\
80 	 ((struct ghes_estatus_node *)(estatus_node) + 1))
81 
82 #define GHES_VENDOR_ENTRY_LEN(gdata_len)                               \
83 	(sizeof(struct ghes_vendor_record_entry) + (gdata_len))
84 #define GHES_GDATA_FROM_VENDOR_ENTRY(vendor_entry)                     \
85 	((struct acpi_hest_generic_data *)                              \
86 	((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
87 
88 /*
89  *  NMI-like notifications vary by architecture, before the compiler can prune
90  *  unused static functions it needs a value for these enums.
91  */
92 #ifndef CONFIG_ARM_SDE_INTERFACE
93 #define FIX_APEI_GHES_SDEI_NORMAL	__end_of_fixed_addresses
94 #define FIX_APEI_GHES_SDEI_CRITICAL	__end_of_fixed_addresses
95 #endif
96 
97 static inline bool is_hest_type_generic_v2(struct ghes *ghes)
98 {
99 	return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
100 }
101 
102 /*
103  * This driver isn't really modular, however for the time being,
104  * continuing to use module_param is the easiest way to remain
105  * compatible with existing boot arg use cases.
106  */
107 bool ghes_disable;
108 module_param_named(disable, ghes_disable, bool, 0);
109 
110 /*
111  * All error sources notified with HED (Hardware Error Device) share a
112  * single notifier callback, so they need to be linked and checked one
113  * by one. This holds true for NMI too.
114  *
115  * RCU is used for these lists, so ghes_list_mutex is only used for
116  * list changing, not for traversing.
117  */
118 static LIST_HEAD(ghes_hed);
119 static DEFINE_MUTEX(ghes_list_mutex);
120 
121 /*
122  * Because the memory area used to transfer hardware error information
123  * from BIOS to Linux can be determined only in NMI, IRQ or timer
124  * handler, but general ioremap can not be used in atomic context, so
125  * the fixmap is used instead.
126  *
127  * This spinlock is used to prevent the fixmap entry from being used
128  * simultaneously.
129  */
130 static DEFINE_SPINLOCK(ghes_notify_lock_irq);
131 
132 struct ghes_vendor_record_entry {
133 	struct work_struct work;
134 	int error_severity;
135 	char vendor_record[];
136 };
137 
138 static struct gen_pool *ghes_estatus_pool;
139 static unsigned long ghes_estatus_pool_size_request;
140 
141 static struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
142 static atomic_t ghes_estatus_cache_alloced;
143 
144 static int ghes_panic_timeout __read_mostly = 30;
145 
146 static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
147 {
148 	phys_addr_t paddr;
149 	pgprot_t prot;
150 
151 	paddr = PFN_PHYS(pfn);
152 	prot = arch_apei_get_mem_attribute(paddr);
153 	__set_fixmap(fixmap_idx, paddr, prot);
154 
155 	return (void __iomem *) __fix_to_virt(fixmap_idx);
156 }
157 
158 static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
159 {
160 	int _idx = virt_to_fix((unsigned long)vaddr);
161 
162 	WARN_ON_ONCE(fixmap_idx != _idx);
163 	clear_fixmap(fixmap_idx);
164 }
165 
166 int ghes_estatus_pool_init(int num_ghes)
167 {
168 	unsigned long addr, len;
169 	int rc;
170 
171 	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
172 	if (!ghes_estatus_pool)
173 		return -ENOMEM;
174 
175 	len = GHES_ESTATUS_CACHE_AVG_SIZE * GHES_ESTATUS_CACHE_ALLOCED_MAX;
176 	len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);
177 
178 	ghes_estatus_pool_size_request = PAGE_ALIGN(len);
179 	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
180 	if (!addr)
181 		goto err_pool_alloc;
182 
183 	rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
184 	if (rc)
185 		goto err_pool_add;
186 
187 	return 0;
188 
189 err_pool_add:
190 	vfree((void *)addr);
191 
192 err_pool_alloc:
193 	gen_pool_destroy(ghes_estatus_pool);
194 
195 	return -ENOMEM;
196 }
197 
198 static int map_gen_v2(struct ghes *ghes)
199 {
200 	return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
201 }
202 
203 static void unmap_gen_v2(struct ghes *ghes)
204 {
205 	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
206 }
207 
208 static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
209 {
210 	int rc;
211 	u64 val = 0;
212 
213 	rc = apei_read(&val, &gv2->read_ack_register);
214 	if (rc)
215 		return;
216 
217 	val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;
218 	val |= gv2->read_ack_write    << gv2->read_ack_register.bit_offset;
219 
220 	apei_write(val, &gv2->read_ack_register);
221 }
222 
223 static struct ghes *ghes_new(struct acpi_hest_generic *generic)
224 {
225 	struct ghes *ghes;
226 	unsigned int error_block_length;
227 	int rc;
228 
229 	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
230 	if (!ghes)
231 		return ERR_PTR(-ENOMEM);
232 
233 	ghes->generic = generic;
234 	if (is_hest_type_generic_v2(ghes)) {
235 		rc = map_gen_v2(ghes);
236 		if (rc)
237 			goto err_free;
238 	}
239 
240 	rc = apei_map_generic_address(&generic->error_status_address);
241 	if (rc)
242 		goto err_unmap_read_ack_addr;
243 	error_block_length = generic->error_block_length;
244 	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
245 		pr_warn(FW_WARN GHES_PFX
246 			"Error status block length is too long: %u for "
247 			"generic hardware error source: %d.\n",
248 			error_block_length, generic->header.source_id);
249 		error_block_length = GHES_ESTATUS_MAX_SIZE;
250 	}
251 	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
252 	if (!ghes->estatus) {
253 		rc = -ENOMEM;
254 		goto err_unmap_status_addr;
255 	}
256 
257 	return ghes;
258 
259 err_unmap_status_addr:
260 	apei_unmap_generic_address(&generic->error_status_address);
261 err_unmap_read_ack_addr:
262 	if (is_hest_type_generic_v2(ghes))
263 		unmap_gen_v2(ghes);
264 err_free:
265 	kfree(ghes);
266 	return ERR_PTR(rc);
267 }
268 
269 static void ghes_fini(struct ghes *ghes)
270 {
271 	kfree(ghes->estatus);
272 	apei_unmap_generic_address(&ghes->generic->error_status_address);
273 	if (is_hest_type_generic_v2(ghes))
274 		unmap_gen_v2(ghes);
275 }
276 
277 static inline int ghes_severity(int severity)
278 {
279 	switch (severity) {
280 	case CPER_SEV_INFORMATIONAL:
281 		return GHES_SEV_NO;
282 	case CPER_SEV_CORRECTED:
283 		return GHES_SEV_CORRECTED;
284 	case CPER_SEV_RECOVERABLE:
285 		return GHES_SEV_RECOVERABLE;
286 	case CPER_SEV_FATAL:
287 		return GHES_SEV_PANIC;
288 	default:
289 		/* Unknown, go panic */
290 		return GHES_SEV_PANIC;
291 	}
292 }
293 
294 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
295 				  int from_phys,
296 				  enum fixed_addresses fixmap_idx)
297 {
298 	void __iomem *vaddr;
299 	u64 offset;
300 	u32 trunk;
301 
302 	while (len > 0) {
303 		offset = paddr - (paddr & PAGE_MASK);
304 		vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx);
305 		trunk = PAGE_SIZE - offset;
306 		trunk = min(trunk, len);
307 		if (from_phys)
308 			memcpy_fromio(buffer, vaddr + offset, trunk);
309 		else
310 			memcpy_toio(vaddr + offset, buffer, trunk);
311 		len -= trunk;
312 		paddr += trunk;
313 		buffer += trunk;
314 		ghes_unmap(vaddr, fixmap_idx);
315 	}
316 }
317 
318 /* Check the top-level record header has an appropriate size. */
319 static int __ghes_check_estatus(struct ghes *ghes,
320 				struct acpi_hest_generic_status *estatus)
321 {
322 	u32 len = cper_estatus_len(estatus);
323 
324 	if (len < sizeof(*estatus)) {
325 		pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
326 		return -EIO;
327 	}
328 
329 	if (len > ghes->generic->error_block_length) {
330 		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
331 		return -EIO;
332 	}
333 
334 	if (cper_estatus_check_header(estatus)) {
335 		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
336 		return -EIO;
337 	}
338 
339 	return 0;
340 }
341 
342 /* Read the CPER block, returning its address, and header in estatus. */
343 static int __ghes_peek_estatus(struct ghes *ghes,
344 			       struct acpi_hest_generic_status *estatus,
345 			       u64 *buf_paddr, enum fixed_addresses fixmap_idx)
346 {
347 	struct acpi_hest_generic *g = ghes->generic;
348 	int rc;
349 
350 	rc = apei_read(buf_paddr, &g->error_status_address);
351 	if (rc) {
352 		*buf_paddr = 0;
353 		pr_warn_ratelimited(FW_WARN GHES_PFX
354 "Failed to read error status block address for hardware error source: %d.\n",
355 				   g->header.source_id);
356 		return -EIO;
357 	}
358 	if (!*buf_paddr)
359 		return -ENOENT;
360 
361 	ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
362 			      fixmap_idx);
363 	if (!estatus->block_status) {
364 		*buf_paddr = 0;
365 		return -ENOENT;
366 	}
367 
368 	return 0;
369 }
370 
371 static int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
372 			       u64 buf_paddr, enum fixed_addresses fixmap_idx,
373 			       size_t buf_len)
374 {
375 	ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
376 	if (cper_estatus_check(estatus)) {
377 		pr_warn_ratelimited(FW_WARN GHES_PFX
378 				    "Failed to read error status block!\n");
379 		return -EIO;
380 	}
381 
382 	return 0;
383 }
384 
385 static int ghes_read_estatus(struct ghes *ghes,
386 			     struct acpi_hest_generic_status *estatus,
387 			     u64 *buf_paddr, enum fixed_addresses fixmap_idx)
388 {
389 	int rc;
390 
391 	rc = __ghes_peek_estatus(ghes, estatus, buf_paddr, fixmap_idx);
392 	if (rc)
393 		return rc;
394 
395 	rc = __ghes_check_estatus(ghes, estatus);
396 	if (rc)
397 		return rc;
398 
399 	return __ghes_read_estatus(estatus, *buf_paddr, fixmap_idx,
400 				   cper_estatus_len(estatus));
401 }
402 
403 static void ghes_clear_estatus(struct ghes *ghes,
404 			       struct acpi_hest_generic_status *estatus,
405 			       u64 buf_paddr, enum fixed_addresses fixmap_idx)
406 {
407 	estatus->block_status = 0;
408 
409 	if (!buf_paddr)
410 		return;
411 
412 	ghes_copy_tofrom_phys(estatus, buf_paddr,
413 			      sizeof(estatus->block_status), 0,
414 			      fixmap_idx);
415 
416 	/*
417 	 * GHESv2 type HEST entries introduce support for error acknowledgment,
418 	 * so only acknowledge the error if this support is present.
419 	 */
420 	if (is_hest_type_generic_v2(ghes))
421 		ghes_ack_error(ghes->generic_v2);
422 }
423 
424 /*
425  * Called as task_work before returning to user-space.
426  * Ensure any queued work has been done before we return to the context that
427  * triggered the notification.
428  */
429 static void ghes_kick_task_work(struct callback_head *head)
430 {
431 	struct acpi_hest_generic_status *estatus;
432 	struct ghes_estatus_node *estatus_node;
433 	u32 node_len;
434 
435 	estatus_node = container_of(head, struct ghes_estatus_node, task_work);
436 	if (IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
437 		memory_failure_queue_kick(estatus_node->task_work_cpu);
438 
439 	estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
440 	node_len = GHES_ESTATUS_NODE_LEN(cper_estatus_len(estatus));
441 	gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, node_len);
442 }
443 
444 static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
445 				       int sev)
446 {
447 	unsigned long pfn;
448 	int flags = -1;
449 	int sec_sev = ghes_severity(gdata->error_severity);
450 	struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
451 
452 	if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
453 		return false;
454 
455 	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
456 		return false;
457 
458 	pfn = mem_err->physical_addr >> PAGE_SHIFT;
459 	if (!pfn_valid(pfn)) {
460 		pr_warn_ratelimited(FW_WARN GHES_PFX
461 		"Invalid address in generic error data: %#llx\n",
462 		mem_err->physical_addr);
463 		return false;
464 	}
465 
466 	/* iff following two events can be handled properly by now */
467 	if (sec_sev == GHES_SEV_CORRECTED &&
468 	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
469 		flags = MF_SOFT_OFFLINE;
470 	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
471 		flags = 0;
472 
473 	if (flags != -1) {
474 		memory_failure_queue(pfn, flags);
475 		return true;
476 	}
477 
478 	return false;
479 }
480 
481 /*
482  * PCIe AER errors need to be sent to the AER driver for reporting and
483  * recovery. The GHES severities map to the following AER severities and
484  * require the following handling:
485  *
486  * GHES_SEV_CORRECTABLE -> AER_CORRECTABLE
487  *     These need to be reported by the AER driver but no recovery is
488  *     necessary.
489  * GHES_SEV_RECOVERABLE -> AER_NONFATAL
490  * GHES_SEV_RECOVERABLE && CPER_SEC_RESET -> AER_FATAL
491  *     These both need to be reported and recovered from by the AER driver.
492  * GHES_SEV_PANIC does not make it to this handling since the kernel must
493  *     panic.
494  */
495 static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
496 {
497 #ifdef CONFIG_ACPI_APEI_PCIEAER
498 	struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
499 
500 	if (pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
501 	    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
502 		unsigned int devfn;
503 		int aer_severity;
504 
505 		devfn = PCI_DEVFN(pcie_err->device_id.device,
506 				  pcie_err->device_id.function);
507 		aer_severity = cper_severity_to_aer(gdata->error_severity);
508 
509 		/*
510 		 * If firmware reset the component to contain
511 		 * the error, we must reinitialize it before
512 		 * use, so treat it as a fatal AER error.
513 		 */
514 		if (gdata->flags & CPER_SEC_RESET)
515 			aer_severity = AER_FATAL;
516 
517 		aer_recover_queue(pcie_err->device_id.segment,
518 				  pcie_err->device_id.bus,
519 				  devfn, aer_severity,
520 				  (struct aer_capability_regs *)
521 				  pcie_err->aer_info);
522 	}
523 #endif
524 }
525 
526 static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
527 
528 int ghes_register_vendor_record_notifier(struct notifier_block *nb)
529 {
530 	return blocking_notifier_chain_register(&vendor_record_notify_list, nb);
531 }
532 EXPORT_SYMBOL_GPL(ghes_register_vendor_record_notifier);
533 
534 void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
535 {
536 	blocking_notifier_chain_unregister(&vendor_record_notify_list, nb);
537 }
538 EXPORT_SYMBOL_GPL(ghes_unregister_vendor_record_notifier);
539 
540 static void ghes_vendor_record_work_func(struct work_struct *work)
541 {
542 	struct ghes_vendor_record_entry *entry;
543 	struct acpi_hest_generic_data *gdata;
544 	u32 len;
545 
546 	entry = container_of(work, struct ghes_vendor_record_entry, work);
547 	gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
548 
549 	blocking_notifier_call_chain(&vendor_record_notify_list,
550 				     entry->error_severity, gdata);
551 
552 	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
553 	gen_pool_free(ghes_estatus_pool, (unsigned long)entry, len);
554 }
555 
556 static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
557 					  int sev)
558 {
559 	struct acpi_hest_generic_data *copied_gdata;
560 	struct ghes_vendor_record_entry *entry;
561 	u32 len;
562 
563 	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
564 	entry = (void *)gen_pool_alloc(ghes_estatus_pool, len);
565 	if (!entry)
566 		return;
567 
568 	copied_gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
569 	memcpy(copied_gdata, gdata, acpi_hest_get_record_size(gdata));
570 	entry->error_severity = sev;
571 
572 	INIT_WORK(&entry->work, ghes_vendor_record_work_func);
573 	schedule_work(&entry->work);
574 }
575 
576 static bool ghes_do_proc(struct ghes *ghes,
577 			 const struct acpi_hest_generic_status *estatus)
578 {
579 	int sev, sec_sev;
580 	struct acpi_hest_generic_data *gdata;
581 	guid_t *sec_type;
582 	const guid_t *fru_id = &guid_null;
583 	char *fru_text = "";
584 	bool queued = false;
585 
586 	sev = ghes_severity(estatus->error_severity);
587 	apei_estatus_for_each_section(estatus, gdata) {
588 		sec_type = (guid_t *)gdata->section_type;
589 		sec_sev = ghes_severity(gdata->error_severity);
590 		if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
591 			fru_id = (guid_t *)gdata->fru_id;
592 
593 		if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
594 			fru_text = gdata->fru_text;
595 
596 		if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
597 			struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
598 
599 			ghes_edac_report_mem_error(sev, mem_err);
600 
601 			arch_apei_report_mem_error(sev, mem_err);
602 			queued = ghes_handle_memory_failure(gdata, sev);
603 		}
604 		else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
605 			ghes_handle_aer(gdata);
606 		}
607 		else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
608 			struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
609 
610 			log_arm_hw_error(err);
611 		} else {
612 			void *err = acpi_hest_get_payload(gdata);
613 
614 			ghes_defer_non_standard_event(gdata, sev);
615 			log_non_standard_event(sec_type, fru_id, fru_text,
616 					       sec_sev, err,
617 					       gdata->error_data_length);
618 		}
619 	}
620 
621 	return queued;
622 }
623 
624 static void __ghes_print_estatus(const char *pfx,
625 				 const struct acpi_hest_generic *generic,
626 				 const struct acpi_hest_generic_status *estatus)
627 {
628 	static atomic_t seqno;
629 	unsigned int curr_seqno;
630 	char pfx_seq[64];
631 
632 	if (pfx == NULL) {
633 		if (ghes_severity(estatus->error_severity) <=
634 		    GHES_SEV_CORRECTED)
635 			pfx = KERN_WARNING;
636 		else
637 			pfx = KERN_ERR;
638 	}
639 	curr_seqno = atomic_inc_return(&seqno);
640 	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
641 	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
642 	       pfx_seq, generic->header.source_id);
643 	cper_estatus_print(pfx_seq, estatus);
644 }
645 
646 static int ghes_print_estatus(const char *pfx,
647 			      const struct acpi_hest_generic *generic,
648 			      const struct acpi_hest_generic_status *estatus)
649 {
650 	/* Not more than 2 messages every 5 seconds */
651 	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
652 	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
653 	struct ratelimit_state *ratelimit;
654 
655 	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
656 		ratelimit = &ratelimit_corrected;
657 	else
658 		ratelimit = &ratelimit_uncorrected;
659 	if (__ratelimit(ratelimit)) {
660 		__ghes_print_estatus(pfx, generic, estatus);
661 		return 1;
662 	}
663 	return 0;
664 }
665 
666 /*
667  * GHES error status reporting throttle, to report more kinds of
668  * errors, instead of just most frequently occurred errors.
669  */
670 static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
671 {
672 	u32 len;
673 	int i, cached = 0;
674 	unsigned long long now;
675 	struct ghes_estatus_cache *cache;
676 	struct acpi_hest_generic_status *cache_estatus;
677 
678 	len = cper_estatus_len(estatus);
679 	rcu_read_lock();
680 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
681 		cache = rcu_dereference(ghes_estatus_caches[i]);
682 		if (cache == NULL)
683 			continue;
684 		if (len != cache->estatus_len)
685 			continue;
686 		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
687 		if (memcmp(estatus, cache_estatus, len))
688 			continue;
689 		atomic_inc(&cache->count);
690 		now = sched_clock();
691 		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
692 			cached = 1;
693 		break;
694 	}
695 	rcu_read_unlock();
696 	return cached;
697 }
698 
699 static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
700 	struct acpi_hest_generic *generic,
701 	struct acpi_hest_generic_status *estatus)
702 {
703 	int alloced;
704 	u32 len, cache_len;
705 	struct ghes_estatus_cache *cache;
706 	struct acpi_hest_generic_status *cache_estatus;
707 
708 	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
709 	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
710 		atomic_dec(&ghes_estatus_cache_alloced);
711 		return NULL;
712 	}
713 	len = cper_estatus_len(estatus);
714 	cache_len = GHES_ESTATUS_CACHE_LEN(len);
715 	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
716 	if (!cache) {
717 		atomic_dec(&ghes_estatus_cache_alloced);
718 		return NULL;
719 	}
720 	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
721 	memcpy(cache_estatus, estatus, len);
722 	cache->estatus_len = len;
723 	atomic_set(&cache->count, 0);
724 	cache->generic = generic;
725 	cache->time_in = sched_clock();
726 	return cache;
727 }
728 
729 static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
730 {
731 	u32 len;
732 
733 	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
734 	len = GHES_ESTATUS_CACHE_LEN(len);
735 	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
736 	atomic_dec(&ghes_estatus_cache_alloced);
737 }
738 
739 static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
740 {
741 	struct ghes_estatus_cache *cache;
742 
743 	cache = container_of(head, struct ghes_estatus_cache, rcu);
744 	ghes_estatus_cache_free(cache);
745 }
746 
747 static void ghes_estatus_cache_add(
748 	struct acpi_hest_generic *generic,
749 	struct acpi_hest_generic_status *estatus)
750 {
751 	int i, slot = -1, count;
752 	unsigned long long now, duration, period, max_period = 0;
753 	struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
754 
755 	new_cache = ghes_estatus_cache_alloc(generic, estatus);
756 	if (new_cache == NULL)
757 		return;
758 	rcu_read_lock();
759 	now = sched_clock();
760 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
761 		cache = rcu_dereference(ghes_estatus_caches[i]);
762 		if (cache == NULL) {
763 			slot = i;
764 			slot_cache = NULL;
765 			break;
766 		}
767 		duration = now - cache->time_in;
768 		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
769 			slot = i;
770 			slot_cache = cache;
771 			break;
772 		}
773 		count = atomic_read(&cache->count);
774 		period = duration;
775 		do_div(period, (count + 1));
776 		if (period > max_period) {
777 			max_period = period;
778 			slot = i;
779 			slot_cache = cache;
780 		}
781 	}
782 	/* new_cache must be put into array after its contents are written */
783 	smp_wmb();
784 	if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
785 				  slot_cache, new_cache) == slot_cache) {
786 		if (slot_cache)
787 			call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
788 	} else
789 		ghes_estatus_cache_free(new_cache);
790 	rcu_read_unlock();
791 }
792 
793 static void __ghes_panic(struct ghes *ghes,
794 			 struct acpi_hest_generic_status *estatus,
795 			 u64 buf_paddr, enum fixed_addresses fixmap_idx)
796 {
797 	__ghes_print_estatus(KERN_EMERG, ghes->generic, estatus);
798 
799 	ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
800 
801 	/* reboot to log the error! */
802 	if (!panic_timeout)
803 		panic_timeout = ghes_panic_timeout;
804 	panic("Fatal hardware error!");
805 }
806 
807 static int ghes_proc(struct ghes *ghes)
808 {
809 	struct acpi_hest_generic_status *estatus = ghes->estatus;
810 	u64 buf_paddr;
811 	int rc;
812 
813 	rc = ghes_read_estatus(ghes, estatus, &buf_paddr, FIX_APEI_GHES_IRQ);
814 	if (rc)
815 		goto out;
816 
817 	if (ghes_severity(estatus->error_severity) >= GHES_SEV_PANIC)
818 		__ghes_panic(ghes, estatus, buf_paddr, FIX_APEI_GHES_IRQ);
819 
820 	if (!ghes_estatus_cached(estatus)) {
821 		if (ghes_print_estatus(NULL, ghes->generic, estatus))
822 			ghes_estatus_cache_add(ghes->generic, estatus);
823 	}
824 	ghes_do_proc(ghes, estatus);
825 
826 out:
827 	ghes_clear_estatus(ghes, estatus, buf_paddr, FIX_APEI_GHES_IRQ);
828 
829 	return rc;
830 }
831 
832 static void ghes_add_timer(struct ghes *ghes)
833 {
834 	struct acpi_hest_generic *g = ghes->generic;
835 	unsigned long expire;
836 
837 	if (!g->notify.poll_interval) {
838 		pr_warn(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
839 			g->header.source_id);
840 		return;
841 	}
842 	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
843 	ghes->timer.expires = round_jiffies_relative(expire);
844 	add_timer(&ghes->timer);
845 }
846 
847 static void ghes_poll_func(struct timer_list *t)
848 {
849 	struct ghes *ghes = from_timer(ghes, t, timer);
850 	unsigned long flags;
851 
852 	spin_lock_irqsave(&ghes_notify_lock_irq, flags);
853 	ghes_proc(ghes);
854 	spin_unlock_irqrestore(&ghes_notify_lock_irq, flags);
855 	if (!(ghes->flags & GHES_EXITING))
856 		ghes_add_timer(ghes);
857 }
858 
859 static irqreturn_t ghes_irq_func(int irq, void *data)
860 {
861 	struct ghes *ghes = data;
862 	unsigned long flags;
863 	int rc;
864 
865 	spin_lock_irqsave(&ghes_notify_lock_irq, flags);
866 	rc = ghes_proc(ghes);
867 	spin_unlock_irqrestore(&ghes_notify_lock_irq, flags);
868 	if (rc)
869 		return IRQ_NONE;
870 
871 	return IRQ_HANDLED;
872 }
873 
874 static int ghes_notify_hed(struct notifier_block *this, unsigned long event,
875 			   void *data)
876 {
877 	struct ghes *ghes;
878 	unsigned long flags;
879 	int ret = NOTIFY_DONE;
880 
881 	spin_lock_irqsave(&ghes_notify_lock_irq, flags);
882 	rcu_read_lock();
883 	list_for_each_entry_rcu(ghes, &ghes_hed, list) {
884 		if (!ghes_proc(ghes))
885 			ret = NOTIFY_OK;
886 	}
887 	rcu_read_unlock();
888 	spin_unlock_irqrestore(&ghes_notify_lock_irq, flags);
889 
890 	return ret;
891 }
892 
893 static struct notifier_block ghes_notifier_hed = {
894 	.notifier_call = ghes_notify_hed,
895 };
896 
897 /*
898  * Handlers for CPER records may not be NMI safe. For example,
899  * memory_failure_queue() takes spinlocks and calls schedule_work_on().
900  * In any NMI-like handler, memory from ghes_estatus_pool is used to save
901  * estatus, and added to the ghes_estatus_llist. irq_work_queue() causes
902  * ghes_proc_in_irq() to run in IRQ context where each estatus in
903  * ghes_estatus_llist is processed.
904  *
905  * Memory from the ghes_estatus_pool is also used with the ghes_estatus_cache
906  * to suppress frequent messages.
907  */
908 static struct llist_head ghes_estatus_llist;
909 static struct irq_work ghes_proc_irq_work;
910 
911 static void ghes_proc_in_irq(struct irq_work *irq_work)
912 {
913 	struct llist_node *llnode, *next;
914 	struct ghes_estatus_node *estatus_node;
915 	struct acpi_hest_generic *generic;
916 	struct acpi_hest_generic_status *estatus;
917 	bool task_work_pending;
918 	u32 len, node_len;
919 	int ret;
920 
921 	llnode = llist_del_all(&ghes_estatus_llist);
922 	/*
923 	 * Because the time order of estatus in list is reversed,
924 	 * revert it back to proper order.
925 	 */
926 	llnode = llist_reverse_order(llnode);
927 	while (llnode) {
928 		next = llnode->next;
929 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
930 					   llnode);
931 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
932 		len = cper_estatus_len(estatus);
933 		node_len = GHES_ESTATUS_NODE_LEN(len);
934 		task_work_pending = ghes_do_proc(estatus_node->ghes, estatus);
935 		if (!ghes_estatus_cached(estatus)) {
936 			generic = estatus_node->generic;
937 			if (ghes_print_estatus(NULL, generic, estatus))
938 				ghes_estatus_cache_add(generic, estatus);
939 		}
940 
941 		if (task_work_pending && current->mm != &init_mm) {
942 			estatus_node->task_work.func = ghes_kick_task_work;
943 			estatus_node->task_work_cpu = smp_processor_id();
944 			ret = task_work_add(current, &estatus_node->task_work,
945 					    TWA_RESUME);
946 			if (ret)
947 				estatus_node->task_work.func = NULL;
948 		}
949 
950 		if (!estatus_node->task_work.func)
951 			gen_pool_free(ghes_estatus_pool,
952 				      (unsigned long)estatus_node, node_len);
953 
954 		llnode = next;
955 	}
956 }
957 
958 static void ghes_print_queued_estatus(void)
959 {
960 	struct llist_node *llnode;
961 	struct ghes_estatus_node *estatus_node;
962 	struct acpi_hest_generic *generic;
963 	struct acpi_hest_generic_status *estatus;
964 
965 	llnode = llist_del_all(&ghes_estatus_llist);
966 	/*
967 	 * Because the time order of estatus in list is reversed,
968 	 * revert it back to proper order.
969 	 */
970 	llnode = llist_reverse_order(llnode);
971 	while (llnode) {
972 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
973 					   llnode);
974 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
975 		generic = estatus_node->generic;
976 		ghes_print_estatus(NULL, generic, estatus);
977 		llnode = llnode->next;
978 	}
979 }
980 
981 static int ghes_in_nmi_queue_one_entry(struct ghes *ghes,
982 				       enum fixed_addresses fixmap_idx)
983 {
984 	struct acpi_hest_generic_status *estatus, tmp_header;
985 	struct ghes_estatus_node *estatus_node;
986 	u32 len, node_len;
987 	u64 buf_paddr;
988 	int sev, rc;
989 
990 	if (!IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG))
991 		return -EOPNOTSUPP;
992 
993 	rc = __ghes_peek_estatus(ghes, &tmp_header, &buf_paddr, fixmap_idx);
994 	if (rc) {
995 		ghes_clear_estatus(ghes, &tmp_header, buf_paddr, fixmap_idx);
996 		return rc;
997 	}
998 
999 	rc = __ghes_check_estatus(ghes, &tmp_header);
1000 	if (rc) {
1001 		ghes_clear_estatus(ghes, &tmp_header, buf_paddr, fixmap_idx);
1002 		return rc;
1003 	}
1004 
1005 	len = cper_estatus_len(&tmp_header);
1006 	node_len = GHES_ESTATUS_NODE_LEN(len);
1007 	estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, node_len);
1008 	if (!estatus_node)
1009 		return -ENOMEM;
1010 
1011 	estatus_node->ghes = ghes;
1012 	estatus_node->generic = ghes->generic;
1013 	estatus_node->task_work.func = NULL;
1014 	estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
1015 
1016 	if (__ghes_read_estatus(estatus, buf_paddr, fixmap_idx, len)) {
1017 		ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
1018 		rc = -ENOENT;
1019 		goto no_work;
1020 	}
1021 
1022 	sev = ghes_severity(estatus->error_severity);
1023 	if (sev >= GHES_SEV_PANIC) {
1024 		ghes_print_queued_estatus();
1025 		__ghes_panic(ghes, estatus, buf_paddr, fixmap_idx);
1026 	}
1027 
1028 	ghes_clear_estatus(ghes, &tmp_header, buf_paddr, fixmap_idx);
1029 
1030 	/* This error has been reported before, don't process it again. */
1031 	if (ghes_estatus_cached(estatus))
1032 		goto no_work;
1033 
1034 	llist_add(&estatus_node->llnode, &ghes_estatus_llist);
1035 
1036 	return rc;
1037 
1038 no_work:
1039 	gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
1040 		      node_len);
1041 
1042 	return rc;
1043 }
1044 
1045 static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list,
1046 				       enum fixed_addresses fixmap_idx)
1047 {
1048 	int ret = -ENOENT;
1049 	struct ghes *ghes;
1050 
1051 	rcu_read_lock();
1052 	list_for_each_entry_rcu(ghes, rcu_list, list) {
1053 		if (!ghes_in_nmi_queue_one_entry(ghes, fixmap_idx))
1054 			ret = 0;
1055 	}
1056 	rcu_read_unlock();
1057 
1058 	if (IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && !ret)
1059 		irq_work_queue(&ghes_proc_irq_work);
1060 
1061 	return ret;
1062 }
1063 
1064 #ifdef CONFIG_ACPI_APEI_SEA
1065 static LIST_HEAD(ghes_sea);
1066 
1067 /*
1068  * Return 0 only if one of the SEA error sources successfully reported an error
1069  * record sent from the firmware.
1070  */
1071 int ghes_notify_sea(void)
1072 {
1073 	static DEFINE_RAW_SPINLOCK(ghes_notify_lock_sea);
1074 	int rv;
1075 
1076 	raw_spin_lock(&ghes_notify_lock_sea);
1077 	rv = ghes_in_nmi_spool_from_list(&ghes_sea, FIX_APEI_GHES_SEA);
1078 	raw_spin_unlock(&ghes_notify_lock_sea);
1079 
1080 	return rv;
1081 }
1082 
1083 static void ghes_sea_add(struct ghes *ghes)
1084 {
1085 	mutex_lock(&ghes_list_mutex);
1086 	list_add_rcu(&ghes->list, &ghes_sea);
1087 	mutex_unlock(&ghes_list_mutex);
1088 }
1089 
1090 static void ghes_sea_remove(struct ghes *ghes)
1091 {
1092 	mutex_lock(&ghes_list_mutex);
1093 	list_del_rcu(&ghes->list);
1094 	mutex_unlock(&ghes_list_mutex);
1095 	synchronize_rcu();
1096 }
1097 #else /* CONFIG_ACPI_APEI_SEA */
1098 static inline void ghes_sea_add(struct ghes *ghes) { }
1099 static inline void ghes_sea_remove(struct ghes *ghes) { }
1100 #endif /* CONFIG_ACPI_APEI_SEA */
1101 
1102 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
1103 /*
1104  * NMI may be triggered on any CPU, so ghes_in_nmi is used for
1105  * having only one concurrent reader.
1106  */
1107 static atomic_t ghes_in_nmi = ATOMIC_INIT(0);
1108 
1109 static LIST_HEAD(ghes_nmi);
1110 
1111 static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
1112 {
1113 	static DEFINE_RAW_SPINLOCK(ghes_notify_lock_nmi);
1114 	int ret = NMI_DONE;
1115 
1116 	if (!atomic_add_unless(&ghes_in_nmi, 1, 1))
1117 		return ret;
1118 
1119 	raw_spin_lock(&ghes_notify_lock_nmi);
1120 	if (!ghes_in_nmi_spool_from_list(&ghes_nmi, FIX_APEI_GHES_NMI))
1121 		ret = NMI_HANDLED;
1122 	raw_spin_unlock(&ghes_notify_lock_nmi);
1123 
1124 	atomic_dec(&ghes_in_nmi);
1125 	return ret;
1126 }
1127 
1128 static void ghes_nmi_add(struct ghes *ghes)
1129 {
1130 	mutex_lock(&ghes_list_mutex);
1131 	if (list_empty(&ghes_nmi))
1132 		register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes");
1133 	list_add_rcu(&ghes->list, &ghes_nmi);
1134 	mutex_unlock(&ghes_list_mutex);
1135 }
1136 
1137 static void ghes_nmi_remove(struct ghes *ghes)
1138 {
1139 	mutex_lock(&ghes_list_mutex);
1140 	list_del_rcu(&ghes->list);
1141 	if (list_empty(&ghes_nmi))
1142 		unregister_nmi_handler(NMI_LOCAL, "ghes");
1143 	mutex_unlock(&ghes_list_mutex);
1144 	/*
1145 	 * To synchronize with NMI handler, ghes can only be
1146 	 * freed after NMI handler finishes.
1147 	 */
1148 	synchronize_rcu();
1149 }
1150 #else /* CONFIG_HAVE_ACPI_APEI_NMI */
1151 static inline void ghes_nmi_add(struct ghes *ghes) { }
1152 static inline void ghes_nmi_remove(struct ghes *ghes) { }
1153 #endif /* CONFIG_HAVE_ACPI_APEI_NMI */
1154 
1155 static void ghes_nmi_init_cxt(void)
1156 {
1157 	init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
1158 }
1159 
1160 static int __ghes_sdei_callback(struct ghes *ghes,
1161 				enum fixed_addresses fixmap_idx)
1162 {
1163 	if (!ghes_in_nmi_queue_one_entry(ghes, fixmap_idx)) {
1164 		irq_work_queue(&ghes_proc_irq_work);
1165 
1166 		return 0;
1167 	}
1168 
1169 	return -ENOENT;
1170 }
1171 
1172 static int ghes_sdei_normal_callback(u32 event_num, struct pt_regs *regs,
1173 				      void *arg)
1174 {
1175 	static DEFINE_RAW_SPINLOCK(ghes_notify_lock_sdei_normal);
1176 	struct ghes *ghes = arg;
1177 	int err;
1178 
1179 	raw_spin_lock(&ghes_notify_lock_sdei_normal);
1180 	err = __ghes_sdei_callback(ghes, FIX_APEI_GHES_SDEI_NORMAL);
1181 	raw_spin_unlock(&ghes_notify_lock_sdei_normal);
1182 
1183 	return err;
1184 }
1185 
1186 static int ghes_sdei_critical_callback(u32 event_num, struct pt_regs *regs,
1187 				       void *arg)
1188 {
1189 	static DEFINE_RAW_SPINLOCK(ghes_notify_lock_sdei_critical);
1190 	struct ghes *ghes = arg;
1191 	int err;
1192 
1193 	raw_spin_lock(&ghes_notify_lock_sdei_critical);
1194 	err = __ghes_sdei_callback(ghes, FIX_APEI_GHES_SDEI_CRITICAL);
1195 	raw_spin_unlock(&ghes_notify_lock_sdei_critical);
1196 
1197 	return err;
1198 }
1199 
1200 static int apei_sdei_register_ghes(struct ghes *ghes)
1201 {
1202 	if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE))
1203 		return -EOPNOTSUPP;
1204 
1205 	return sdei_register_ghes(ghes, ghes_sdei_normal_callback,
1206 				 ghes_sdei_critical_callback);
1207 }
1208 
1209 static int apei_sdei_unregister_ghes(struct ghes *ghes)
1210 {
1211 	if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE))
1212 		return -EOPNOTSUPP;
1213 
1214 	return sdei_unregister_ghes(ghes);
1215 }
1216 
1217 static int ghes_probe(struct platform_device *ghes_dev)
1218 {
1219 	struct acpi_hest_generic *generic;
1220 	struct ghes *ghes = NULL;
1221 	unsigned long flags;
1222 
1223 	int rc = -EINVAL;
1224 
1225 	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
1226 	if (!generic->enabled)
1227 		return -ENODEV;
1228 
1229 	switch (generic->notify.type) {
1230 	case ACPI_HEST_NOTIFY_POLLED:
1231 	case ACPI_HEST_NOTIFY_EXTERNAL:
1232 	case ACPI_HEST_NOTIFY_SCI:
1233 	case ACPI_HEST_NOTIFY_GSIV:
1234 	case ACPI_HEST_NOTIFY_GPIO:
1235 		break;
1236 
1237 	case ACPI_HEST_NOTIFY_SEA:
1238 		if (!IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
1239 			pr_warn(GHES_PFX "Generic hardware error source: %d notified via SEA is not supported\n",
1240 				generic->header.source_id);
1241 			rc = -ENOTSUPP;
1242 			goto err;
1243 		}
1244 		break;
1245 	case ACPI_HEST_NOTIFY_NMI:
1246 		if (!IS_ENABLED(CONFIG_HAVE_ACPI_APEI_NMI)) {
1247 			pr_warn(GHES_PFX "Generic hardware error source: %d notified via NMI interrupt is not supported!\n",
1248 				generic->header.source_id);
1249 			goto err;
1250 		}
1251 		break;
1252 	case ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED:
1253 		if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE)) {
1254 			pr_warn(GHES_PFX "Generic hardware error source: %d notified via SDE Interface is not supported!\n",
1255 				generic->header.source_id);
1256 			goto err;
1257 		}
1258 		break;
1259 	case ACPI_HEST_NOTIFY_LOCAL:
1260 		pr_warn(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
1261 			generic->header.source_id);
1262 		goto err;
1263 	default:
1264 		pr_warn(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
1265 			generic->notify.type, generic->header.source_id);
1266 		goto err;
1267 	}
1268 
1269 	rc = -EIO;
1270 	if (generic->error_block_length <
1271 	    sizeof(struct acpi_hest_generic_status)) {
1272 		pr_warn(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
1273 			generic->error_block_length, generic->header.source_id);
1274 		goto err;
1275 	}
1276 	ghes = ghes_new(generic);
1277 	if (IS_ERR(ghes)) {
1278 		rc = PTR_ERR(ghes);
1279 		ghes = NULL;
1280 		goto err;
1281 	}
1282 
1283 	switch (generic->notify.type) {
1284 	case ACPI_HEST_NOTIFY_POLLED:
1285 		timer_setup(&ghes->timer, ghes_poll_func, 0);
1286 		ghes_add_timer(ghes);
1287 		break;
1288 	case ACPI_HEST_NOTIFY_EXTERNAL:
1289 		/* External interrupt vector is GSI */
1290 		rc = acpi_gsi_to_irq(generic->notify.vector, &ghes->irq);
1291 		if (rc) {
1292 			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
1293 			       generic->header.source_id);
1294 			goto err;
1295 		}
1296 		rc = request_irq(ghes->irq, ghes_irq_func, IRQF_SHARED,
1297 				 "GHES IRQ", ghes);
1298 		if (rc) {
1299 			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
1300 			       generic->header.source_id);
1301 			goto err;
1302 		}
1303 		break;
1304 
1305 	case ACPI_HEST_NOTIFY_SCI:
1306 	case ACPI_HEST_NOTIFY_GSIV:
1307 	case ACPI_HEST_NOTIFY_GPIO:
1308 		mutex_lock(&ghes_list_mutex);
1309 		if (list_empty(&ghes_hed))
1310 			register_acpi_hed_notifier(&ghes_notifier_hed);
1311 		list_add_rcu(&ghes->list, &ghes_hed);
1312 		mutex_unlock(&ghes_list_mutex);
1313 		break;
1314 
1315 	case ACPI_HEST_NOTIFY_SEA:
1316 		ghes_sea_add(ghes);
1317 		break;
1318 	case ACPI_HEST_NOTIFY_NMI:
1319 		ghes_nmi_add(ghes);
1320 		break;
1321 	case ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED:
1322 		rc = apei_sdei_register_ghes(ghes);
1323 		if (rc)
1324 			goto err;
1325 		break;
1326 	default:
1327 		BUG();
1328 	}
1329 
1330 	platform_set_drvdata(ghes_dev, ghes);
1331 
1332 	ghes_edac_register(ghes, &ghes_dev->dev);
1333 
1334 	/* Handle any pending errors right away */
1335 	spin_lock_irqsave(&ghes_notify_lock_irq, flags);
1336 	ghes_proc(ghes);
1337 	spin_unlock_irqrestore(&ghes_notify_lock_irq, flags);
1338 
1339 	return 0;
1340 
1341 err:
1342 	if (ghes) {
1343 		ghes_fini(ghes);
1344 		kfree(ghes);
1345 	}
1346 	return rc;
1347 }
1348 
1349 static int ghes_remove(struct platform_device *ghes_dev)
1350 {
1351 	int rc;
1352 	struct ghes *ghes;
1353 	struct acpi_hest_generic *generic;
1354 
1355 	ghes = platform_get_drvdata(ghes_dev);
1356 	generic = ghes->generic;
1357 
1358 	ghes->flags |= GHES_EXITING;
1359 	switch (generic->notify.type) {
1360 	case ACPI_HEST_NOTIFY_POLLED:
1361 		del_timer_sync(&ghes->timer);
1362 		break;
1363 	case ACPI_HEST_NOTIFY_EXTERNAL:
1364 		free_irq(ghes->irq, ghes);
1365 		break;
1366 
1367 	case ACPI_HEST_NOTIFY_SCI:
1368 	case ACPI_HEST_NOTIFY_GSIV:
1369 	case ACPI_HEST_NOTIFY_GPIO:
1370 		mutex_lock(&ghes_list_mutex);
1371 		list_del_rcu(&ghes->list);
1372 		if (list_empty(&ghes_hed))
1373 			unregister_acpi_hed_notifier(&ghes_notifier_hed);
1374 		mutex_unlock(&ghes_list_mutex);
1375 		synchronize_rcu();
1376 		break;
1377 
1378 	case ACPI_HEST_NOTIFY_SEA:
1379 		ghes_sea_remove(ghes);
1380 		break;
1381 	case ACPI_HEST_NOTIFY_NMI:
1382 		ghes_nmi_remove(ghes);
1383 		break;
1384 	case ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED:
1385 		rc = apei_sdei_unregister_ghes(ghes);
1386 		if (rc)
1387 			return rc;
1388 		break;
1389 	default:
1390 		BUG();
1391 		break;
1392 	}
1393 
1394 	ghes_fini(ghes);
1395 
1396 	ghes_edac_unregister(ghes);
1397 
1398 	kfree(ghes);
1399 
1400 	platform_set_drvdata(ghes_dev, NULL);
1401 
1402 	return 0;
1403 }
1404 
1405 static struct platform_driver ghes_platform_driver = {
1406 	.driver		= {
1407 		.name	= "GHES",
1408 	},
1409 	.probe		= ghes_probe,
1410 	.remove		= ghes_remove,
1411 };
1412 
1413 static int __init ghes_init(void)
1414 {
1415 	int rc;
1416 
1417 	if (acpi_disabled)
1418 		return -ENODEV;
1419 
1420 	switch (hest_disable) {
1421 	case HEST_NOT_FOUND:
1422 		return -ENODEV;
1423 	case HEST_DISABLED:
1424 		pr_info(GHES_PFX "HEST is not enabled!\n");
1425 		return -EINVAL;
1426 	default:
1427 		break;
1428 	}
1429 
1430 	if (ghes_disable) {
1431 		pr_info(GHES_PFX "GHES is not enabled!\n");
1432 		return -EINVAL;
1433 	}
1434 
1435 	ghes_nmi_init_cxt();
1436 
1437 	rc = platform_driver_register(&ghes_platform_driver);
1438 	if (rc)
1439 		goto err;
1440 
1441 	rc = apei_osc_setup();
1442 	if (rc == 0 && osc_sb_apei_support_acked)
1443 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1444 	else if (rc == 0 && !osc_sb_apei_support_acked)
1445 		pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1446 	else if (rc && osc_sb_apei_support_acked)
1447 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1448 	else
1449 		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1450 
1451 	return 0;
1452 err:
1453 	return rc;
1454 }
1455 device_initcall(ghes_init);
1456