xref: /openbmc/linux/drivers/acpi/apei/ghes.c (revision 4f3db074)
1 /*
2  * APEI Generic Hardware Error Source support
3  *
4  * Generic Hardware Error Source provides a way to report platform
5  * hardware errors (such as that from chipset). It works in so called
6  * "Firmware First" mode, that is, hardware errors are reported to
7  * firmware firstly, then reported to Linux by firmware. This way,
8  * some non-standard hardware error registers or non-standard hardware
9  * link can be checked by firmware to produce more hardware error
10  * information for Linux.
11  *
12  * For more information about Generic Hardware Error Source, please
13  * refer to ACPI Specification version 4.0, section 17.3.2.6
14  *
15  * Copyright 2010,2011 Intel Corp.
16  *   Author: Huang Ying <ying.huang@intel.com>
17  *
18  * This program is free software; you can redistribute it and/or
19  * modify it under the terms of the GNU General Public License version
20  * 2 as published by the Free Software Foundation;
21  *
22  * This program is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
30  */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/acpi.h>
36 #include <linux/io.h>
37 #include <linux/interrupt.h>
38 #include <linux/timer.h>
39 #include <linux/cper.h>
40 #include <linux/kdebug.h>
41 #include <linux/platform_device.h>
42 #include <linux/mutex.h>
43 #include <linux/ratelimit.h>
44 #include <linux/vmalloc.h>
45 #include <linux/irq_work.h>
46 #include <linux/llist.h>
47 #include <linux/genalloc.h>
48 #include <linux/pci.h>
49 #include <linux/aer.h>
50 #include <linux/nmi.h>
51 
52 #include <acpi/ghes.h>
53 #include <acpi/apei.h>
54 #include <asm/tlbflush.h>
55 
56 #include "apei-internal.h"
57 
58 #define GHES_PFX	"GHES: "
59 
60 #define GHES_ESTATUS_MAX_SIZE		65536
61 #define GHES_ESOURCE_PREALLOC_MAX_SIZE	65536
62 
63 #define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
64 
65 /* This is just an estimation for memory pool allocation */
66 #define GHES_ESTATUS_CACHE_AVG_SIZE	512
67 
68 #define GHES_ESTATUS_CACHES_SIZE	4
69 
70 #define GHES_ESTATUS_IN_CACHE_MAX_NSEC	10000000000ULL
71 /* Prevent too many caches are allocated because of RCU */
72 #define GHES_ESTATUS_CACHE_ALLOCED_MAX	(GHES_ESTATUS_CACHES_SIZE * 3 / 2)
73 
74 #define GHES_ESTATUS_CACHE_LEN(estatus_len)			\
75 	(sizeof(struct ghes_estatus_cache) + (estatus_len))
76 #define GHES_ESTATUS_FROM_CACHE(estatus_cache)			\
77 	((struct acpi_hest_generic_status *)				\
78 	 ((struct ghes_estatus_cache *)(estatus_cache) + 1))
79 
80 #define GHES_ESTATUS_NODE_LEN(estatus_len)			\
81 	(sizeof(struct ghes_estatus_node) + (estatus_len))
82 #define GHES_ESTATUS_FROM_NODE(estatus_node)			\
83 	((struct acpi_hest_generic_status *)				\
84 	 ((struct ghes_estatus_node *)(estatus_node) + 1))
85 
86 bool ghes_disable;
87 module_param_named(disable, ghes_disable, bool, 0);
88 
89 /*
90  * All error sources notified with SCI shares one notifier function,
91  * so they need to be linked and checked one by one.  This is applied
92  * to NMI too.
93  *
94  * RCU is used for these lists, so ghes_list_mutex is only used for
95  * list changing, not for traversing.
96  */
97 static LIST_HEAD(ghes_sci);
98 static DEFINE_MUTEX(ghes_list_mutex);
99 
100 /*
101  * Because the memory area used to transfer hardware error information
102  * from BIOS to Linux can be determined only in NMI, IRQ or timer
103  * handler, but general ioremap can not be used in atomic context, so
104  * a special version of atomic ioremap is implemented for that.
105  */
106 
107 /*
108  * Two virtual pages are used, one for IRQ/PROCESS context, the other for
109  * NMI context (optionally).
110  */
111 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
112 #define GHES_IOREMAP_PAGES           2
113 #else
114 #define GHES_IOREMAP_PAGES           1
115 #endif
116 #define GHES_IOREMAP_IRQ_PAGE(base)	(base)
117 #define GHES_IOREMAP_NMI_PAGE(base)	((base) + PAGE_SIZE)
118 
119 /* virtual memory area for atomic ioremap */
120 static struct vm_struct *ghes_ioremap_area;
121 /*
122  * These 2 spinlock is used to prevent atomic ioremap virtual memory
123  * area from being mapped simultaneously.
124  */
125 static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
126 static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
127 
128 static struct gen_pool *ghes_estatus_pool;
129 static unsigned long ghes_estatus_pool_size_request;
130 
131 static struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
132 static atomic_t ghes_estatus_cache_alloced;
133 
134 static int ghes_ioremap_init(void)
135 {
136 	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
137 		VM_IOREMAP, VMALLOC_START, VMALLOC_END);
138 	if (!ghes_ioremap_area) {
139 		pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
140 		return -ENOMEM;
141 	}
142 
143 	return 0;
144 }
145 
146 static void ghes_ioremap_exit(void)
147 {
148 	free_vm_area(ghes_ioremap_area);
149 }
150 
151 static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
152 {
153 	unsigned long vaddr;
154 
155 	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
156 	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
157 			   pfn << PAGE_SHIFT, PAGE_KERNEL);
158 
159 	return (void __iomem *)vaddr;
160 }
161 
162 static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
163 {
164 	unsigned long vaddr;
165 
166 	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
167 	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
168 			   pfn << PAGE_SHIFT, PAGE_KERNEL);
169 
170 	return (void __iomem *)vaddr;
171 }
172 
173 static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
174 {
175 	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
176 	void *base = ghes_ioremap_area->addr;
177 
178 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
179 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
180 	arch_apei_flush_tlb_one(vaddr);
181 }
182 
183 static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
184 {
185 	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
186 	void *base = ghes_ioremap_area->addr;
187 
188 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
189 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
190 	arch_apei_flush_tlb_one(vaddr);
191 }
192 
193 static int ghes_estatus_pool_init(void)
194 {
195 	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
196 	if (!ghes_estatus_pool)
197 		return -ENOMEM;
198 	return 0;
199 }
200 
201 static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,
202 					      struct gen_pool_chunk *chunk,
203 					      void *data)
204 {
205 	free_page(chunk->start_addr);
206 }
207 
208 static void ghes_estatus_pool_exit(void)
209 {
210 	gen_pool_for_each_chunk(ghes_estatus_pool,
211 				ghes_estatus_pool_free_chunk_page, NULL);
212 	gen_pool_destroy(ghes_estatus_pool);
213 }
214 
215 static int ghes_estatus_pool_expand(unsigned long len)
216 {
217 	unsigned long i, pages, size, addr;
218 	int ret;
219 
220 	ghes_estatus_pool_size_request += PAGE_ALIGN(len);
221 	size = gen_pool_size(ghes_estatus_pool);
222 	if (size >= ghes_estatus_pool_size_request)
223 		return 0;
224 	pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;
225 	for (i = 0; i < pages; i++) {
226 		addr = __get_free_page(GFP_KERNEL);
227 		if (!addr)
228 			return -ENOMEM;
229 		ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);
230 		if (ret)
231 			return ret;
232 	}
233 
234 	return 0;
235 }
236 
237 static struct ghes *ghes_new(struct acpi_hest_generic *generic)
238 {
239 	struct ghes *ghes;
240 	unsigned int error_block_length;
241 	int rc;
242 
243 	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
244 	if (!ghes)
245 		return ERR_PTR(-ENOMEM);
246 	ghes->generic = generic;
247 	rc = apei_map_generic_address(&generic->error_status_address);
248 	if (rc)
249 		goto err_free;
250 	error_block_length = generic->error_block_length;
251 	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
252 		pr_warning(FW_WARN GHES_PFX
253 			   "Error status block length is too long: %u for "
254 			   "generic hardware error source: %d.\n",
255 			   error_block_length, generic->header.source_id);
256 		error_block_length = GHES_ESTATUS_MAX_SIZE;
257 	}
258 	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
259 	if (!ghes->estatus) {
260 		rc = -ENOMEM;
261 		goto err_unmap;
262 	}
263 
264 	return ghes;
265 
266 err_unmap:
267 	apei_unmap_generic_address(&generic->error_status_address);
268 err_free:
269 	kfree(ghes);
270 	return ERR_PTR(rc);
271 }
272 
273 static void ghes_fini(struct ghes *ghes)
274 {
275 	kfree(ghes->estatus);
276 	apei_unmap_generic_address(&ghes->generic->error_status_address);
277 }
278 
279 static inline int ghes_severity(int severity)
280 {
281 	switch (severity) {
282 	case CPER_SEV_INFORMATIONAL:
283 		return GHES_SEV_NO;
284 	case CPER_SEV_CORRECTED:
285 		return GHES_SEV_CORRECTED;
286 	case CPER_SEV_RECOVERABLE:
287 		return GHES_SEV_RECOVERABLE;
288 	case CPER_SEV_FATAL:
289 		return GHES_SEV_PANIC;
290 	default:
291 		/* Unknown, go panic */
292 		return GHES_SEV_PANIC;
293 	}
294 }
295 
296 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
297 				  int from_phys)
298 {
299 	void __iomem *vaddr;
300 	unsigned long flags = 0;
301 	int in_nmi = in_nmi();
302 	u64 offset;
303 	u32 trunk;
304 
305 	while (len > 0) {
306 		offset = paddr - (paddr & PAGE_MASK);
307 		if (in_nmi) {
308 			raw_spin_lock(&ghes_ioremap_lock_nmi);
309 			vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
310 		} else {
311 			spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
312 			vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
313 		}
314 		trunk = PAGE_SIZE - offset;
315 		trunk = min(trunk, len);
316 		if (from_phys)
317 			memcpy_fromio(buffer, vaddr + offset, trunk);
318 		else
319 			memcpy_toio(vaddr + offset, buffer, trunk);
320 		len -= trunk;
321 		paddr += trunk;
322 		buffer += trunk;
323 		if (in_nmi) {
324 			ghes_iounmap_nmi(vaddr);
325 			raw_spin_unlock(&ghes_ioremap_lock_nmi);
326 		} else {
327 			ghes_iounmap_irq(vaddr);
328 			spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
329 		}
330 	}
331 }
332 
333 static int ghes_read_estatus(struct ghes *ghes, int silent)
334 {
335 	struct acpi_hest_generic *g = ghes->generic;
336 	u64 buf_paddr;
337 	u32 len;
338 	int rc;
339 
340 	rc = apei_read(&buf_paddr, &g->error_status_address);
341 	if (rc) {
342 		if (!silent && printk_ratelimit())
343 			pr_warning(FW_WARN GHES_PFX
344 "Failed to read error status block address for hardware error source: %d.\n",
345 				   g->header.source_id);
346 		return -EIO;
347 	}
348 	if (!buf_paddr)
349 		return -ENOENT;
350 
351 	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
352 			      sizeof(*ghes->estatus), 1);
353 	if (!ghes->estatus->block_status)
354 		return -ENOENT;
355 
356 	ghes->buffer_paddr = buf_paddr;
357 	ghes->flags |= GHES_TO_CLEAR;
358 
359 	rc = -EIO;
360 	len = cper_estatus_len(ghes->estatus);
361 	if (len < sizeof(*ghes->estatus))
362 		goto err_read_block;
363 	if (len > ghes->generic->error_block_length)
364 		goto err_read_block;
365 	if (cper_estatus_check_header(ghes->estatus))
366 		goto err_read_block;
367 	ghes_copy_tofrom_phys(ghes->estatus + 1,
368 			      buf_paddr + sizeof(*ghes->estatus),
369 			      len - sizeof(*ghes->estatus), 1);
370 	if (cper_estatus_check(ghes->estatus))
371 		goto err_read_block;
372 	rc = 0;
373 
374 err_read_block:
375 	if (rc && !silent && printk_ratelimit())
376 		pr_warning(FW_WARN GHES_PFX
377 			   "Failed to read error status block!\n");
378 	return rc;
379 }
380 
381 static void ghes_clear_estatus(struct ghes *ghes)
382 {
383 	ghes->estatus->block_status = 0;
384 	if (!(ghes->flags & GHES_TO_CLEAR))
385 		return;
386 	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
387 			      sizeof(ghes->estatus->block_status), 0);
388 	ghes->flags &= ~GHES_TO_CLEAR;
389 }
390 
391 static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)
392 {
393 #ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
394 	unsigned long pfn;
395 	int flags = -1;
396 	int sec_sev = ghes_severity(gdata->error_severity);
397 	struct cper_sec_mem_err *mem_err;
398 	mem_err = (struct cper_sec_mem_err *)(gdata + 1);
399 
400 	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
401 		return;
402 
403 	pfn = mem_err->physical_addr >> PAGE_SHIFT;
404 	if (!pfn_valid(pfn)) {
405 		pr_warn_ratelimited(FW_WARN GHES_PFX
406 		"Invalid address in generic error data: %#llx\n",
407 		mem_err->physical_addr);
408 		return;
409 	}
410 
411 	/* iff following two events can be handled properly by now */
412 	if (sec_sev == GHES_SEV_CORRECTED &&
413 	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
414 		flags = MF_SOFT_OFFLINE;
415 	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
416 		flags = 0;
417 
418 	if (flags != -1)
419 		memory_failure_queue(pfn, 0, flags);
420 #endif
421 }
422 
423 static void ghes_do_proc(struct ghes *ghes,
424 			 const struct acpi_hest_generic_status *estatus)
425 {
426 	int sev, sec_sev;
427 	struct acpi_hest_generic_data *gdata;
428 
429 	sev = ghes_severity(estatus->error_severity);
430 	apei_estatus_for_each_section(estatus, gdata) {
431 		sec_sev = ghes_severity(gdata->error_severity);
432 		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
433 				 CPER_SEC_PLATFORM_MEM)) {
434 			struct cper_sec_mem_err *mem_err;
435 			mem_err = (struct cper_sec_mem_err *)(gdata+1);
436 			ghes_edac_report_mem_error(ghes, sev, mem_err);
437 
438 			arch_apei_report_mem_error(sev, mem_err);
439 			ghes_handle_memory_failure(gdata, sev);
440 		}
441 #ifdef CONFIG_ACPI_APEI_PCIEAER
442 		else if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
443 				      CPER_SEC_PCIE)) {
444 			struct cper_sec_pcie *pcie_err;
445 			pcie_err = (struct cper_sec_pcie *)(gdata+1);
446 			if (sev == GHES_SEV_RECOVERABLE &&
447 			    sec_sev == GHES_SEV_RECOVERABLE &&
448 			    pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
449 			    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
450 				unsigned int devfn;
451 				int aer_severity;
452 
453 				devfn = PCI_DEVFN(pcie_err->device_id.device,
454 						  pcie_err->device_id.function);
455 				aer_severity = cper_severity_to_aer(sev);
456 
457 				/*
458 				 * If firmware reset the component to contain
459 				 * the error, we must reinitialize it before
460 				 * use, so treat it as a fatal AER error.
461 				 */
462 				if (gdata->flags & CPER_SEC_RESET)
463 					aer_severity = AER_FATAL;
464 
465 				aer_recover_queue(pcie_err->device_id.segment,
466 						  pcie_err->device_id.bus,
467 						  devfn, aer_severity,
468 						  (struct aer_capability_regs *)
469 						  pcie_err->aer_info);
470 			}
471 
472 		}
473 #endif
474 	}
475 }
476 
477 static void __ghes_print_estatus(const char *pfx,
478 				 const struct acpi_hest_generic *generic,
479 				 const struct acpi_hest_generic_status *estatus)
480 {
481 	static atomic_t seqno;
482 	unsigned int curr_seqno;
483 	char pfx_seq[64];
484 
485 	if (pfx == NULL) {
486 		if (ghes_severity(estatus->error_severity) <=
487 		    GHES_SEV_CORRECTED)
488 			pfx = KERN_WARNING;
489 		else
490 			pfx = KERN_ERR;
491 	}
492 	curr_seqno = atomic_inc_return(&seqno);
493 	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
494 	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
495 	       pfx_seq, generic->header.source_id);
496 	cper_estatus_print(pfx_seq, estatus);
497 }
498 
499 static int ghes_print_estatus(const char *pfx,
500 			      const struct acpi_hest_generic *generic,
501 			      const struct acpi_hest_generic_status *estatus)
502 {
503 	/* Not more than 2 messages every 5 seconds */
504 	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
505 	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
506 	struct ratelimit_state *ratelimit;
507 
508 	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
509 		ratelimit = &ratelimit_corrected;
510 	else
511 		ratelimit = &ratelimit_uncorrected;
512 	if (__ratelimit(ratelimit)) {
513 		__ghes_print_estatus(pfx, generic, estatus);
514 		return 1;
515 	}
516 	return 0;
517 }
518 
519 /*
520  * GHES error status reporting throttle, to report more kinds of
521  * errors, instead of just most frequently occurred errors.
522  */
523 static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
524 {
525 	u32 len;
526 	int i, cached = 0;
527 	unsigned long long now;
528 	struct ghes_estatus_cache *cache;
529 	struct acpi_hest_generic_status *cache_estatus;
530 
531 	len = cper_estatus_len(estatus);
532 	rcu_read_lock();
533 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
534 		cache = rcu_dereference(ghes_estatus_caches[i]);
535 		if (cache == NULL)
536 			continue;
537 		if (len != cache->estatus_len)
538 			continue;
539 		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
540 		if (memcmp(estatus, cache_estatus, len))
541 			continue;
542 		atomic_inc(&cache->count);
543 		now = sched_clock();
544 		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
545 			cached = 1;
546 		break;
547 	}
548 	rcu_read_unlock();
549 	return cached;
550 }
551 
552 static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
553 	struct acpi_hest_generic *generic,
554 	struct acpi_hest_generic_status *estatus)
555 {
556 	int alloced;
557 	u32 len, cache_len;
558 	struct ghes_estatus_cache *cache;
559 	struct acpi_hest_generic_status *cache_estatus;
560 
561 	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
562 	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
563 		atomic_dec(&ghes_estatus_cache_alloced);
564 		return NULL;
565 	}
566 	len = cper_estatus_len(estatus);
567 	cache_len = GHES_ESTATUS_CACHE_LEN(len);
568 	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
569 	if (!cache) {
570 		atomic_dec(&ghes_estatus_cache_alloced);
571 		return NULL;
572 	}
573 	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
574 	memcpy(cache_estatus, estatus, len);
575 	cache->estatus_len = len;
576 	atomic_set(&cache->count, 0);
577 	cache->generic = generic;
578 	cache->time_in = sched_clock();
579 	return cache;
580 }
581 
582 static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
583 {
584 	u32 len;
585 
586 	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
587 	len = GHES_ESTATUS_CACHE_LEN(len);
588 	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
589 	atomic_dec(&ghes_estatus_cache_alloced);
590 }
591 
592 static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
593 {
594 	struct ghes_estatus_cache *cache;
595 
596 	cache = container_of(head, struct ghes_estatus_cache, rcu);
597 	ghes_estatus_cache_free(cache);
598 }
599 
600 static void ghes_estatus_cache_add(
601 	struct acpi_hest_generic *generic,
602 	struct acpi_hest_generic_status *estatus)
603 {
604 	int i, slot = -1, count;
605 	unsigned long long now, duration, period, max_period = 0;
606 	struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
607 
608 	new_cache = ghes_estatus_cache_alloc(generic, estatus);
609 	if (new_cache == NULL)
610 		return;
611 	rcu_read_lock();
612 	now = sched_clock();
613 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
614 		cache = rcu_dereference(ghes_estatus_caches[i]);
615 		if (cache == NULL) {
616 			slot = i;
617 			slot_cache = NULL;
618 			break;
619 		}
620 		duration = now - cache->time_in;
621 		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
622 			slot = i;
623 			slot_cache = cache;
624 			break;
625 		}
626 		count = atomic_read(&cache->count);
627 		period = duration;
628 		do_div(period, (count + 1));
629 		if (period > max_period) {
630 			max_period = period;
631 			slot = i;
632 			slot_cache = cache;
633 		}
634 	}
635 	/* new_cache must be put into array after its contents are written */
636 	smp_wmb();
637 	if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
638 				  slot_cache, new_cache) == slot_cache) {
639 		if (slot_cache)
640 			call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
641 	} else
642 		ghes_estatus_cache_free(new_cache);
643 	rcu_read_unlock();
644 }
645 
646 static int ghes_proc(struct ghes *ghes)
647 {
648 	int rc;
649 
650 	rc = ghes_read_estatus(ghes, 0);
651 	if (rc)
652 		goto out;
653 	if (!ghes_estatus_cached(ghes->estatus)) {
654 		if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
655 			ghes_estatus_cache_add(ghes->generic, ghes->estatus);
656 	}
657 	ghes_do_proc(ghes, ghes->estatus);
658 out:
659 	ghes_clear_estatus(ghes);
660 	return 0;
661 }
662 
663 static void ghes_add_timer(struct ghes *ghes)
664 {
665 	struct acpi_hest_generic *g = ghes->generic;
666 	unsigned long expire;
667 
668 	if (!g->notify.poll_interval) {
669 		pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
670 			   g->header.source_id);
671 		return;
672 	}
673 	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
674 	ghes->timer.expires = round_jiffies_relative(expire);
675 	add_timer(&ghes->timer);
676 }
677 
678 static void ghes_poll_func(unsigned long data)
679 {
680 	struct ghes *ghes = (void *)data;
681 
682 	ghes_proc(ghes);
683 	if (!(ghes->flags & GHES_EXITING))
684 		ghes_add_timer(ghes);
685 }
686 
687 static irqreturn_t ghes_irq_func(int irq, void *data)
688 {
689 	struct ghes *ghes = data;
690 	int rc;
691 
692 	rc = ghes_proc(ghes);
693 	if (rc)
694 		return IRQ_NONE;
695 
696 	return IRQ_HANDLED;
697 }
698 
699 static int ghes_notify_sci(struct notifier_block *this,
700 				  unsigned long event, void *data)
701 {
702 	struct ghes *ghes;
703 	int ret = NOTIFY_DONE;
704 
705 	rcu_read_lock();
706 	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
707 		if (!ghes_proc(ghes))
708 			ret = NOTIFY_OK;
709 	}
710 	rcu_read_unlock();
711 
712 	return ret;
713 }
714 
715 static struct notifier_block ghes_notifier_sci = {
716 	.notifier_call = ghes_notify_sci,
717 };
718 
719 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
720 /*
721  * printk is not safe in NMI context.  So in NMI handler, we allocate
722  * required memory from lock-less memory allocator
723  * (ghes_estatus_pool), save estatus into it, put them into lock-less
724  * list (ghes_estatus_llist), then delay printk into IRQ context via
725  * irq_work (ghes_proc_irq_work).  ghes_estatus_size_request record
726  * required pool size by all NMI error source.
727  */
728 static struct llist_head ghes_estatus_llist;
729 static struct irq_work ghes_proc_irq_work;
730 
731 /*
732  * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
733  * mutual exclusion.
734  */
735 static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
736 
737 static LIST_HEAD(ghes_nmi);
738 
739 static int ghes_panic_timeout	__read_mostly = 30;
740 
741 static void ghes_proc_in_irq(struct irq_work *irq_work)
742 {
743 	struct llist_node *llnode, *next;
744 	struct ghes_estatus_node *estatus_node;
745 	struct acpi_hest_generic *generic;
746 	struct acpi_hest_generic_status *estatus;
747 	u32 len, node_len;
748 
749 	llnode = llist_del_all(&ghes_estatus_llist);
750 	/*
751 	 * Because the time order of estatus in list is reversed,
752 	 * revert it back to proper order.
753 	 */
754 	llnode = llist_reverse_order(llnode);
755 	while (llnode) {
756 		next = llnode->next;
757 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
758 					   llnode);
759 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
760 		len = cper_estatus_len(estatus);
761 		node_len = GHES_ESTATUS_NODE_LEN(len);
762 		ghes_do_proc(estatus_node->ghes, estatus);
763 		if (!ghes_estatus_cached(estatus)) {
764 			generic = estatus_node->generic;
765 			if (ghes_print_estatus(NULL, generic, estatus))
766 				ghes_estatus_cache_add(generic, estatus);
767 		}
768 		gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
769 			      node_len);
770 		llnode = next;
771 	}
772 }
773 
774 static void ghes_print_queued_estatus(void)
775 {
776 	struct llist_node *llnode;
777 	struct ghes_estatus_node *estatus_node;
778 	struct acpi_hest_generic *generic;
779 	struct acpi_hest_generic_status *estatus;
780 	u32 len, node_len;
781 
782 	llnode = llist_del_all(&ghes_estatus_llist);
783 	/*
784 	 * Because the time order of estatus in list is reversed,
785 	 * revert it back to proper order.
786 	 */
787 	llnode = llist_reverse_order(llnode);
788 	while (llnode) {
789 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
790 					   llnode);
791 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
792 		len = cper_estatus_len(estatus);
793 		node_len = GHES_ESTATUS_NODE_LEN(len);
794 		generic = estatus_node->generic;
795 		ghes_print_estatus(NULL, generic, estatus);
796 		llnode = llnode->next;
797 	}
798 }
799 
800 static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
801 {
802 	struct ghes *ghes, *ghes_global = NULL;
803 	int sev, sev_global = -1;
804 	int ret = NMI_DONE;
805 
806 	raw_spin_lock(&ghes_nmi_lock);
807 	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
808 		if (ghes_read_estatus(ghes, 1)) {
809 			ghes_clear_estatus(ghes);
810 			continue;
811 		}
812 		sev = ghes_severity(ghes->estatus->error_severity);
813 		if (sev > sev_global) {
814 			sev_global = sev;
815 			ghes_global = ghes;
816 		}
817 		ret = NMI_HANDLED;
818 	}
819 
820 	if (ret == NMI_DONE)
821 		goto out;
822 
823 	if (sev_global >= GHES_SEV_PANIC) {
824 		oops_begin();
825 		ghes_print_queued_estatus();
826 		__ghes_print_estatus(KERN_EMERG, ghes_global->generic,
827 				     ghes_global->estatus);
828 		/* reboot to log the error! */
829 		if (panic_timeout == 0)
830 			panic_timeout = ghes_panic_timeout;
831 		panic("Fatal hardware error!");
832 	}
833 
834 	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
835 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
836 		u32 len, node_len;
837 		struct ghes_estatus_node *estatus_node;
838 		struct acpi_hest_generic_status *estatus;
839 #endif
840 		if (!(ghes->flags & GHES_TO_CLEAR))
841 			continue;
842 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
843 		if (ghes_estatus_cached(ghes->estatus))
844 			goto next;
845 		/* Save estatus for further processing in IRQ context */
846 		len = cper_estatus_len(ghes->estatus);
847 		node_len = GHES_ESTATUS_NODE_LEN(len);
848 		estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
849 						      node_len);
850 		if (estatus_node) {
851 			estatus_node->ghes = ghes;
852 			estatus_node->generic = ghes->generic;
853 			estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
854 			memcpy(estatus, ghes->estatus, len);
855 			llist_add(&estatus_node->llnode, &ghes_estatus_llist);
856 		}
857 next:
858 #endif
859 		ghes_clear_estatus(ghes);
860 	}
861 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
862 	irq_work_queue(&ghes_proc_irq_work);
863 #endif
864 
865 out:
866 	raw_spin_unlock(&ghes_nmi_lock);
867 	return ret;
868 }
869 
870 static unsigned long ghes_esource_prealloc_size(
871 	const struct acpi_hest_generic *generic)
872 {
873 	unsigned long block_length, prealloc_records, prealloc_size;
874 
875 	block_length = min_t(unsigned long, generic->error_block_length,
876 			     GHES_ESTATUS_MAX_SIZE);
877 	prealloc_records = max_t(unsigned long,
878 				 generic->records_to_preallocate, 1);
879 	prealloc_size = min_t(unsigned long, block_length * prealloc_records,
880 			      GHES_ESOURCE_PREALLOC_MAX_SIZE);
881 
882 	return prealloc_size;
883 }
884 
885 static void ghes_estatus_pool_shrink(unsigned long len)
886 {
887 	ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
888 }
889 
890 static void ghes_nmi_add(struct ghes *ghes)
891 {
892 	unsigned long len;
893 
894 	len = ghes_esource_prealloc_size(ghes->generic);
895 	ghes_estatus_pool_expand(len);
896 	mutex_lock(&ghes_list_mutex);
897 	if (list_empty(&ghes_nmi))
898 		register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes");
899 	list_add_rcu(&ghes->list, &ghes_nmi);
900 	mutex_unlock(&ghes_list_mutex);
901 }
902 
903 static void ghes_nmi_remove(struct ghes *ghes)
904 {
905 	unsigned long len;
906 
907 	mutex_lock(&ghes_list_mutex);
908 	list_del_rcu(&ghes->list);
909 	if (list_empty(&ghes_nmi))
910 		unregister_nmi_handler(NMI_LOCAL, "ghes");
911 	mutex_unlock(&ghes_list_mutex);
912 	/*
913 	 * To synchronize with NMI handler, ghes can only be
914 	 * freed after NMI handler finishes.
915 	 */
916 	synchronize_rcu();
917 	len = ghes_esource_prealloc_size(ghes->generic);
918 	ghes_estatus_pool_shrink(len);
919 }
920 
921 static void ghes_nmi_init_cxt(void)
922 {
923 	init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
924 }
925 #else /* CONFIG_HAVE_ACPI_APEI_NMI */
926 static inline void ghes_nmi_add(struct ghes *ghes)
927 {
928 	pr_err(GHES_PFX "ID: %d, trying to add NMI notification which is not supported!\n",
929 	       ghes->generic->header.source_id);
930 	BUG();
931 }
932 
933 static inline void ghes_nmi_remove(struct ghes *ghes)
934 {
935 	pr_err(GHES_PFX "ID: %d, trying to remove NMI notification which is not supported!\n",
936 	       ghes->generic->header.source_id);
937 	BUG();
938 }
939 
940 static inline void ghes_nmi_init_cxt(void)
941 {
942 }
943 #endif /* CONFIG_HAVE_ACPI_APEI_NMI */
944 
945 static int ghes_probe(struct platform_device *ghes_dev)
946 {
947 	struct acpi_hest_generic *generic;
948 	struct ghes *ghes = NULL;
949 
950 	int rc = -EINVAL;
951 
952 	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
953 	if (!generic->enabled)
954 		return -ENODEV;
955 
956 	switch (generic->notify.type) {
957 	case ACPI_HEST_NOTIFY_POLLED:
958 	case ACPI_HEST_NOTIFY_EXTERNAL:
959 	case ACPI_HEST_NOTIFY_SCI:
960 		break;
961 	case ACPI_HEST_NOTIFY_NMI:
962 		if (!IS_ENABLED(CONFIG_HAVE_ACPI_APEI_NMI)) {
963 			pr_warn(GHES_PFX "Generic hardware error source: %d notified via NMI interrupt is not supported!\n",
964 				generic->header.source_id);
965 			goto err;
966 		}
967 		break;
968 	case ACPI_HEST_NOTIFY_LOCAL:
969 		pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
970 			   generic->header.source_id);
971 		goto err;
972 	default:
973 		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
974 			   generic->notify.type, generic->header.source_id);
975 		goto err;
976 	}
977 
978 	rc = -EIO;
979 	if (generic->error_block_length <
980 	    sizeof(struct acpi_hest_generic_status)) {
981 		pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
982 			   generic->error_block_length,
983 			   generic->header.source_id);
984 		goto err;
985 	}
986 	ghes = ghes_new(generic);
987 	if (IS_ERR(ghes)) {
988 		rc = PTR_ERR(ghes);
989 		ghes = NULL;
990 		goto err;
991 	}
992 
993 	rc = ghes_edac_register(ghes, &ghes_dev->dev);
994 	if (rc < 0)
995 		goto err;
996 
997 	switch (generic->notify.type) {
998 	case ACPI_HEST_NOTIFY_POLLED:
999 		ghes->timer.function = ghes_poll_func;
1000 		ghes->timer.data = (unsigned long)ghes;
1001 		init_timer_deferrable(&ghes->timer);
1002 		ghes_add_timer(ghes);
1003 		break;
1004 	case ACPI_HEST_NOTIFY_EXTERNAL:
1005 		/* External interrupt vector is GSI */
1006 		rc = acpi_gsi_to_irq(generic->notify.vector, &ghes->irq);
1007 		if (rc) {
1008 			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
1009 			       generic->header.source_id);
1010 			goto err_edac_unreg;
1011 		}
1012 		rc = request_irq(ghes->irq, ghes_irq_func, 0, "GHES IRQ", ghes);
1013 		if (rc) {
1014 			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
1015 			       generic->header.source_id);
1016 			goto err_edac_unreg;
1017 		}
1018 		break;
1019 	case ACPI_HEST_NOTIFY_SCI:
1020 		mutex_lock(&ghes_list_mutex);
1021 		if (list_empty(&ghes_sci))
1022 			register_acpi_hed_notifier(&ghes_notifier_sci);
1023 		list_add_rcu(&ghes->list, &ghes_sci);
1024 		mutex_unlock(&ghes_list_mutex);
1025 		break;
1026 	case ACPI_HEST_NOTIFY_NMI:
1027 		ghes_nmi_add(ghes);
1028 		break;
1029 	default:
1030 		BUG();
1031 	}
1032 	platform_set_drvdata(ghes_dev, ghes);
1033 
1034 	return 0;
1035 err_edac_unreg:
1036 	ghes_edac_unregister(ghes);
1037 err:
1038 	if (ghes) {
1039 		ghes_fini(ghes);
1040 		kfree(ghes);
1041 	}
1042 	return rc;
1043 }
1044 
1045 static int ghes_remove(struct platform_device *ghes_dev)
1046 {
1047 	struct ghes *ghes;
1048 	struct acpi_hest_generic *generic;
1049 
1050 	ghes = platform_get_drvdata(ghes_dev);
1051 	generic = ghes->generic;
1052 
1053 	ghes->flags |= GHES_EXITING;
1054 	switch (generic->notify.type) {
1055 	case ACPI_HEST_NOTIFY_POLLED:
1056 		del_timer_sync(&ghes->timer);
1057 		break;
1058 	case ACPI_HEST_NOTIFY_EXTERNAL:
1059 		free_irq(ghes->irq, ghes);
1060 		break;
1061 	case ACPI_HEST_NOTIFY_SCI:
1062 		mutex_lock(&ghes_list_mutex);
1063 		list_del_rcu(&ghes->list);
1064 		if (list_empty(&ghes_sci))
1065 			unregister_acpi_hed_notifier(&ghes_notifier_sci);
1066 		mutex_unlock(&ghes_list_mutex);
1067 		break;
1068 	case ACPI_HEST_NOTIFY_NMI:
1069 		ghes_nmi_remove(ghes);
1070 		break;
1071 	default:
1072 		BUG();
1073 		break;
1074 	}
1075 
1076 	ghes_fini(ghes);
1077 
1078 	ghes_edac_unregister(ghes);
1079 
1080 	kfree(ghes);
1081 
1082 	platform_set_drvdata(ghes_dev, NULL);
1083 
1084 	return 0;
1085 }
1086 
1087 static struct platform_driver ghes_platform_driver = {
1088 	.driver		= {
1089 		.name	= "GHES",
1090 	},
1091 	.probe		= ghes_probe,
1092 	.remove		= ghes_remove,
1093 };
1094 
1095 static int __init ghes_init(void)
1096 {
1097 	int rc;
1098 
1099 	if (acpi_disabled)
1100 		return -ENODEV;
1101 
1102 	if (hest_disable) {
1103 		pr_info(GHES_PFX "HEST is not enabled!\n");
1104 		return -EINVAL;
1105 	}
1106 
1107 	if (ghes_disable) {
1108 		pr_info(GHES_PFX "GHES is not enabled!\n");
1109 		return -EINVAL;
1110 	}
1111 
1112 	ghes_nmi_init_cxt();
1113 
1114 	rc = ghes_ioremap_init();
1115 	if (rc)
1116 		goto err;
1117 
1118 	rc = ghes_estatus_pool_init();
1119 	if (rc)
1120 		goto err_ioremap_exit;
1121 
1122 	rc = ghes_estatus_pool_expand(GHES_ESTATUS_CACHE_AVG_SIZE *
1123 				      GHES_ESTATUS_CACHE_ALLOCED_MAX);
1124 	if (rc)
1125 		goto err_pool_exit;
1126 
1127 	rc = platform_driver_register(&ghes_platform_driver);
1128 	if (rc)
1129 		goto err_pool_exit;
1130 
1131 	rc = apei_osc_setup();
1132 	if (rc == 0 && osc_sb_apei_support_acked)
1133 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1134 	else if (rc == 0 && !osc_sb_apei_support_acked)
1135 		pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1136 	else if (rc && osc_sb_apei_support_acked)
1137 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1138 	else
1139 		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1140 
1141 	return 0;
1142 err_pool_exit:
1143 	ghes_estatus_pool_exit();
1144 err_ioremap_exit:
1145 	ghes_ioremap_exit();
1146 err:
1147 	return rc;
1148 }
1149 
1150 static void __exit ghes_exit(void)
1151 {
1152 	platform_driver_unregister(&ghes_platform_driver);
1153 	ghes_estatus_pool_exit();
1154 	ghes_ioremap_exit();
1155 }
1156 
1157 module_init(ghes_init);
1158 module_exit(ghes_exit);
1159 
1160 MODULE_AUTHOR("Huang Ying");
1161 MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1162 MODULE_LICENSE("GPL");
1163 MODULE_ALIAS("platform:GHES");
1164