xref: /openbmc/linux/drivers/acpi/apei/ghes.c (revision 84d517f3)
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 
51 #include <acpi/ghes.h>
52 #include <asm/mce.h>
53 #include <asm/tlbflush.h>
54 #include <asm/nmi.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_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_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 static int ghes_panic_timeout	__read_mostly = 30;
90 
91 /*
92  * All error sources notified with SCI shares one notifier function,
93  * so they need to be linked and checked one by one.  This is applied
94  * to NMI too.
95  *
96  * RCU is used for these lists, so ghes_list_mutex is only used for
97  * list changing, not for traversing.
98  */
99 static LIST_HEAD(ghes_sci);
100 static LIST_HEAD(ghes_nmi);
101 static DEFINE_MUTEX(ghes_list_mutex);
102 
103 /*
104  * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
105  * mutual exclusion.
106  */
107 static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
108 
109 /*
110  * Because the memory area used to transfer hardware error information
111  * from BIOS to Linux can be determined only in NMI, IRQ or timer
112  * handler, but general ioremap can not be used in atomic context, so
113  * a special version of atomic ioremap is implemented for that.
114  */
115 
116 /*
117  * Two virtual pages are used, one for NMI context, the other for
118  * IRQ/PROCESS context
119  */
120 #define GHES_IOREMAP_PAGES		2
121 #define GHES_IOREMAP_NMI_PAGE(base)	(base)
122 #define GHES_IOREMAP_IRQ_PAGE(base)	((base) + PAGE_SIZE)
123 
124 /* virtual memory area for atomic ioremap */
125 static struct vm_struct *ghes_ioremap_area;
126 /*
127  * These 2 spinlock is used to prevent atomic ioremap virtual memory
128  * area from being mapped simultaneously.
129  */
130 static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
131 static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
132 
133 /*
134  * printk is not safe in NMI context.  So in NMI handler, we allocate
135  * required memory from lock-less memory allocator
136  * (ghes_estatus_pool), save estatus into it, put them into lock-less
137  * list (ghes_estatus_llist), then delay printk into IRQ context via
138  * irq_work (ghes_proc_irq_work).  ghes_estatus_size_request record
139  * required pool size by all NMI error source.
140  */
141 static struct gen_pool *ghes_estatus_pool;
142 static unsigned long ghes_estatus_pool_size_request;
143 static struct llist_head ghes_estatus_llist;
144 static struct irq_work ghes_proc_irq_work;
145 
146 struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
147 static atomic_t ghes_estatus_cache_alloced;
148 
149 static int ghes_ioremap_init(void)
150 {
151 	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
152 		VM_IOREMAP, VMALLOC_START, VMALLOC_END);
153 	if (!ghes_ioremap_area) {
154 		pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
155 		return -ENOMEM;
156 	}
157 
158 	return 0;
159 }
160 
161 static void ghes_ioremap_exit(void)
162 {
163 	free_vm_area(ghes_ioremap_area);
164 }
165 
166 static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
167 {
168 	unsigned long vaddr;
169 
170 	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
171 	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
172 			   pfn << PAGE_SHIFT, PAGE_KERNEL);
173 
174 	return (void __iomem *)vaddr;
175 }
176 
177 static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
178 {
179 	unsigned long vaddr;
180 
181 	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
182 	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
183 			   pfn << PAGE_SHIFT, PAGE_KERNEL);
184 
185 	return (void __iomem *)vaddr;
186 }
187 
188 static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
189 {
190 	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
191 	void *base = ghes_ioremap_area->addr;
192 
193 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
194 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
195 	__flush_tlb_one(vaddr);
196 }
197 
198 static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
199 {
200 	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
201 	void *base = ghes_ioremap_area->addr;
202 
203 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
204 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
205 	__flush_tlb_one(vaddr);
206 }
207 
208 static int ghes_estatus_pool_init(void)
209 {
210 	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
211 	if (!ghes_estatus_pool)
212 		return -ENOMEM;
213 	return 0;
214 }
215 
216 static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,
217 					      struct gen_pool_chunk *chunk,
218 					      void *data)
219 {
220 	free_page(chunk->start_addr);
221 }
222 
223 static void ghes_estatus_pool_exit(void)
224 {
225 	gen_pool_for_each_chunk(ghes_estatus_pool,
226 				ghes_estatus_pool_free_chunk_page, NULL);
227 	gen_pool_destroy(ghes_estatus_pool);
228 }
229 
230 static int ghes_estatus_pool_expand(unsigned long len)
231 {
232 	unsigned long i, pages, size, addr;
233 	int ret;
234 
235 	ghes_estatus_pool_size_request += PAGE_ALIGN(len);
236 	size = gen_pool_size(ghes_estatus_pool);
237 	if (size >= ghes_estatus_pool_size_request)
238 		return 0;
239 	pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;
240 	for (i = 0; i < pages; i++) {
241 		addr = __get_free_page(GFP_KERNEL);
242 		if (!addr)
243 			return -ENOMEM;
244 		ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);
245 		if (ret)
246 			return ret;
247 	}
248 
249 	return 0;
250 }
251 
252 static void ghes_estatus_pool_shrink(unsigned long len)
253 {
254 	ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
255 }
256 
257 static struct ghes *ghes_new(struct acpi_hest_generic *generic)
258 {
259 	struct ghes *ghes;
260 	unsigned int error_block_length;
261 	int rc;
262 
263 	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
264 	if (!ghes)
265 		return ERR_PTR(-ENOMEM);
266 	ghes->generic = generic;
267 	rc = apei_map_generic_address(&generic->error_status_address);
268 	if (rc)
269 		goto err_free;
270 	error_block_length = generic->error_block_length;
271 	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
272 		pr_warning(FW_WARN GHES_PFX
273 			   "Error status block length is too long: %u for "
274 			   "generic hardware error source: %d.\n",
275 			   error_block_length, generic->header.source_id);
276 		error_block_length = GHES_ESTATUS_MAX_SIZE;
277 	}
278 	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
279 	if (!ghes->estatus) {
280 		rc = -ENOMEM;
281 		goto err_unmap;
282 	}
283 
284 	return ghes;
285 
286 err_unmap:
287 	apei_unmap_generic_address(&generic->error_status_address);
288 err_free:
289 	kfree(ghes);
290 	return ERR_PTR(rc);
291 }
292 
293 static void ghes_fini(struct ghes *ghes)
294 {
295 	kfree(ghes->estatus);
296 	apei_unmap_generic_address(&ghes->generic->error_status_address);
297 }
298 
299 static inline int ghes_severity(int severity)
300 {
301 	switch (severity) {
302 	case CPER_SEV_INFORMATIONAL:
303 		return GHES_SEV_NO;
304 	case CPER_SEV_CORRECTED:
305 		return GHES_SEV_CORRECTED;
306 	case CPER_SEV_RECOVERABLE:
307 		return GHES_SEV_RECOVERABLE;
308 	case CPER_SEV_FATAL:
309 		return GHES_SEV_PANIC;
310 	default:
311 		/* Unknown, go panic */
312 		return GHES_SEV_PANIC;
313 	}
314 }
315 
316 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
317 				  int from_phys)
318 {
319 	void __iomem *vaddr;
320 	unsigned long flags = 0;
321 	int in_nmi = in_nmi();
322 	u64 offset;
323 	u32 trunk;
324 
325 	while (len > 0) {
326 		offset = paddr - (paddr & PAGE_MASK);
327 		if (in_nmi) {
328 			raw_spin_lock(&ghes_ioremap_lock_nmi);
329 			vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
330 		} else {
331 			spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
332 			vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
333 		}
334 		trunk = PAGE_SIZE - offset;
335 		trunk = min(trunk, len);
336 		if (from_phys)
337 			memcpy_fromio(buffer, vaddr + offset, trunk);
338 		else
339 			memcpy_toio(vaddr + offset, buffer, trunk);
340 		len -= trunk;
341 		paddr += trunk;
342 		buffer += trunk;
343 		if (in_nmi) {
344 			ghes_iounmap_nmi(vaddr);
345 			raw_spin_unlock(&ghes_ioremap_lock_nmi);
346 		} else {
347 			ghes_iounmap_irq(vaddr);
348 			spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
349 		}
350 	}
351 }
352 
353 static int ghes_read_estatus(struct ghes *ghes, int silent)
354 {
355 	struct acpi_hest_generic *g = ghes->generic;
356 	u64 buf_paddr;
357 	u32 len;
358 	int rc;
359 
360 	rc = apei_read(&buf_paddr, &g->error_status_address);
361 	if (rc) {
362 		if (!silent && printk_ratelimit())
363 			pr_warning(FW_WARN GHES_PFX
364 "Failed to read error status block address for hardware error source: %d.\n",
365 				   g->header.source_id);
366 		return -EIO;
367 	}
368 	if (!buf_paddr)
369 		return -ENOENT;
370 
371 	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
372 			      sizeof(*ghes->estatus), 1);
373 	if (!ghes->estatus->block_status)
374 		return -ENOENT;
375 
376 	ghes->buffer_paddr = buf_paddr;
377 	ghes->flags |= GHES_TO_CLEAR;
378 
379 	rc = -EIO;
380 	len = cper_estatus_len(ghes->estatus);
381 	if (len < sizeof(*ghes->estatus))
382 		goto err_read_block;
383 	if (len > ghes->generic->error_block_length)
384 		goto err_read_block;
385 	if (cper_estatus_check_header(ghes->estatus))
386 		goto err_read_block;
387 	ghes_copy_tofrom_phys(ghes->estatus + 1,
388 			      buf_paddr + sizeof(*ghes->estatus),
389 			      len - sizeof(*ghes->estatus), 1);
390 	if (cper_estatus_check(ghes->estatus))
391 		goto err_read_block;
392 	rc = 0;
393 
394 err_read_block:
395 	if (rc && !silent && printk_ratelimit())
396 		pr_warning(FW_WARN GHES_PFX
397 			   "Failed to read error status block!\n");
398 	return rc;
399 }
400 
401 static void ghes_clear_estatus(struct ghes *ghes)
402 {
403 	ghes->estatus->block_status = 0;
404 	if (!(ghes->flags & GHES_TO_CLEAR))
405 		return;
406 	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
407 			      sizeof(ghes->estatus->block_status), 0);
408 	ghes->flags &= ~GHES_TO_CLEAR;
409 }
410 
411 static void ghes_handle_memory_failure(struct acpi_generic_data *gdata, int sev)
412 {
413 #ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
414 	unsigned long pfn;
415 	int flags = -1;
416 	int sec_sev = ghes_severity(gdata->error_severity);
417 	struct cper_sec_mem_err *mem_err;
418 	mem_err = (struct cper_sec_mem_err *)(gdata + 1);
419 
420 	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
421 		return;
422 
423 	pfn = mem_err->physical_addr >> PAGE_SHIFT;
424 	if (!pfn_valid(pfn)) {
425 		pr_warn_ratelimited(FW_WARN GHES_PFX
426 		"Invalid address in generic error data: %#llx\n",
427 		mem_err->physical_addr);
428 		return;
429 	}
430 
431 	/* iff following two events can be handled properly by now */
432 	if (sec_sev == GHES_SEV_CORRECTED &&
433 	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
434 		flags = MF_SOFT_OFFLINE;
435 	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
436 		flags = 0;
437 
438 	if (flags != -1)
439 		memory_failure_queue(pfn, 0, flags);
440 #endif
441 }
442 
443 static void ghes_do_proc(struct ghes *ghes,
444 			 const struct acpi_generic_status *estatus)
445 {
446 	int sev, sec_sev;
447 	struct acpi_generic_data *gdata;
448 
449 	sev = ghes_severity(estatus->error_severity);
450 	apei_estatus_for_each_section(estatus, gdata) {
451 		sec_sev = ghes_severity(gdata->error_severity);
452 		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
453 				 CPER_SEC_PLATFORM_MEM)) {
454 			struct cper_sec_mem_err *mem_err;
455 			mem_err = (struct cper_sec_mem_err *)(gdata+1);
456 			ghes_edac_report_mem_error(ghes, sev, mem_err);
457 
458 #ifdef CONFIG_X86_MCE
459 			apei_mce_report_mem_error(sev, mem_err);
460 #endif
461 			ghes_handle_memory_failure(gdata, sev);
462 		}
463 #ifdef CONFIG_ACPI_APEI_PCIEAER
464 		else if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
465 				      CPER_SEC_PCIE)) {
466 			struct cper_sec_pcie *pcie_err;
467 			pcie_err = (struct cper_sec_pcie *)(gdata+1);
468 			if (sev == GHES_SEV_RECOVERABLE &&
469 			    sec_sev == GHES_SEV_RECOVERABLE &&
470 			    pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
471 			    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
472 				unsigned int devfn;
473 				int aer_severity;
474 
475 				devfn = PCI_DEVFN(pcie_err->device_id.device,
476 						  pcie_err->device_id.function);
477 				aer_severity = cper_severity_to_aer(sev);
478 
479 				/*
480 				 * If firmware reset the component to contain
481 				 * the error, we must reinitialize it before
482 				 * use, so treat it as a fatal AER error.
483 				 */
484 				if (gdata->flags & CPER_SEC_RESET)
485 					aer_severity = AER_FATAL;
486 
487 				aer_recover_queue(pcie_err->device_id.segment,
488 						  pcie_err->device_id.bus,
489 						  devfn, aer_severity,
490 						  (struct aer_capability_regs *)
491 						  pcie_err->aer_info);
492 			}
493 
494 		}
495 #endif
496 	}
497 }
498 
499 static void __ghes_print_estatus(const char *pfx,
500 				 const struct acpi_hest_generic *generic,
501 				 const struct acpi_generic_status *estatus)
502 {
503 	static atomic_t seqno;
504 	unsigned int curr_seqno;
505 	char pfx_seq[64];
506 
507 	if (pfx == NULL) {
508 		if (ghes_severity(estatus->error_severity) <=
509 		    GHES_SEV_CORRECTED)
510 			pfx = KERN_WARNING;
511 		else
512 			pfx = KERN_ERR;
513 	}
514 	curr_seqno = atomic_inc_return(&seqno);
515 	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
516 	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
517 	       pfx_seq, generic->header.source_id);
518 	cper_estatus_print(pfx_seq, estatus);
519 }
520 
521 static int ghes_print_estatus(const char *pfx,
522 			      const struct acpi_hest_generic *generic,
523 			      const struct acpi_generic_status *estatus)
524 {
525 	/* Not more than 2 messages every 5 seconds */
526 	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
527 	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
528 	struct ratelimit_state *ratelimit;
529 
530 	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
531 		ratelimit = &ratelimit_corrected;
532 	else
533 		ratelimit = &ratelimit_uncorrected;
534 	if (__ratelimit(ratelimit)) {
535 		__ghes_print_estatus(pfx, generic, estatus);
536 		return 1;
537 	}
538 	return 0;
539 }
540 
541 /*
542  * GHES error status reporting throttle, to report more kinds of
543  * errors, instead of just most frequently occurred errors.
544  */
545 static int ghes_estatus_cached(struct acpi_generic_status *estatus)
546 {
547 	u32 len;
548 	int i, cached = 0;
549 	unsigned long long now;
550 	struct ghes_estatus_cache *cache;
551 	struct acpi_generic_status *cache_estatus;
552 
553 	len = cper_estatus_len(estatus);
554 	rcu_read_lock();
555 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
556 		cache = rcu_dereference(ghes_estatus_caches[i]);
557 		if (cache == NULL)
558 			continue;
559 		if (len != cache->estatus_len)
560 			continue;
561 		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
562 		if (memcmp(estatus, cache_estatus, len))
563 			continue;
564 		atomic_inc(&cache->count);
565 		now = sched_clock();
566 		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
567 			cached = 1;
568 		break;
569 	}
570 	rcu_read_unlock();
571 	return cached;
572 }
573 
574 static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
575 	struct acpi_hest_generic *generic,
576 	struct acpi_generic_status *estatus)
577 {
578 	int alloced;
579 	u32 len, cache_len;
580 	struct ghes_estatus_cache *cache;
581 	struct acpi_generic_status *cache_estatus;
582 
583 	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
584 	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
585 		atomic_dec(&ghes_estatus_cache_alloced);
586 		return NULL;
587 	}
588 	len = cper_estatus_len(estatus);
589 	cache_len = GHES_ESTATUS_CACHE_LEN(len);
590 	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
591 	if (!cache) {
592 		atomic_dec(&ghes_estatus_cache_alloced);
593 		return NULL;
594 	}
595 	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
596 	memcpy(cache_estatus, estatus, len);
597 	cache->estatus_len = len;
598 	atomic_set(&cache->count, 0);
599 	cache->generic = generic;
600 	cache->time_in = sched_clock();
601 	return cache;
602 }
603 
604 static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
605 {
606 	u32 len;
607 
608 	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
609 	len = GHES_ESTATUS_CACHE_LEN(len);
610 	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
611 	atomic_dec(&ghes_estatus_cache_alloced);
612 }
613 
614 static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
615 {
616 	struct ghes_estatus_cache *cache;
617 
618 	cache = container_of(head, struct ghes_estatus_cache, rcu);
619 	ghes_estatus_cache_free(cache);
620 }
621 
622 static void ghes_estatus_cache_add(
623 	struct acpi_hest_generic *generic,
624 	struct acpi_generic_status *estatus)
625 {
626 	int i, slot = -1, count;
627 	unsigned long long now, duration, period, max_period = 0;
628 	struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
629 
630 	new_cache = ghes_estatus_cache_alloc(generic, estatus);
631 	if (new_cache == NULL)
632 		return;
633 	rcu_read_lock();
634 	now = sched_clock();
635 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
636 		cache = rcu_dereference(ghes_estatus_caches[i]);
637 		if (cache == NULL) {
638 			slot = i;
639 			slot_cache = NULL;
640 			break;
641 		}
642 		duration = now - cache->time_in;
643 		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
644 			slot = i;
645 			slot_cache = cache;
646 			break;
647 		}
648 		count = atomic_read(&cache->count);
649 		period = duration;
650 		do_div(period, (count + 1));
651 		if (period > max_period) {
652 			max_period = period;
653 			slot = i;
654 			slot_cache = cache;
655 		}
656 	}
657 	/* new_cache must be put into array after its contents are written */
658 	smp_wmb();
659 	if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
660 				  slot_cache, new_cache) == slot_cache) {
661 		if (slot_cache)
662 			call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
663 	} else
664 		ghes_estatus_cache_free(new_cache);
665 	rcu_read_unlock();
666 }
667 
668 static int ghes_proc(struct ghes *ghes)
669 {
670 	int rc;
671 
672 	rc = ghes_read_estatus(ghes, 0);
673 	if (rc)
674 		goto out;
675 	if (!ghes_estatus_cached(ghes->estatus)) {
676 		if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
677 			ghes_estatus_cache_add(ghes->generic, ghes->estatus);
678 	}
679 	ghes_do_proc(ghes, ghes->estatus);
680 out:
681 	ghes_clear_estatus(ghes);
682 	return 0;
683 }
684 
685 static void ghes_add_timer(struct ghes *ghes)
686 {
687 	struct acpi_hest_generic *g = ghes->generic;
688 	unsigned long expire;
689 
690 	if (!g->notify.poll_interval) {
691 		pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
692 			   g->header.source_id);
693 		return;
694 	}
695 	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
696 	ghes->timer.expires = round_jiffies_relative(expire);
697 	add_timer(&ghes->timer);
698 }
699 
700 static void ghes_poll_func(unsigned long data)
701 {
702 	struct ghes *ghes = (void *)data;
703 
704 	ghes_proc(ghes);
705 	if (!(ghes->flags & GHES_EXITING))
706 		ghes_add_timer(ghes);
707 }
708 
709 static irqreturn_t ghes_irq_func(int irq, void *data)
710 {
711 	struct ghes *ghes = data;
712 	int rc;
713 
714 	rc = ghes_proc(ghes);
715 	if (rc)
716 		return IRQ_NONE;
717 
718 	return IRQ_HANDLED;
719 }
720 
721 static int ghes_notify_sci(struct notifier_block *this,
722 				  unsigned long event, void *data)
723 {
724 	struct ghes *ghes;
725 	int ret = NOTIFY_DONE;
726 
727 	rcu_read_lock();
728 	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
729 		if (!ghes_proc(ghes))
730 			ret = NOTIFY_OK;
731 	}
732 	rcu_read_unlock();
733 
734 	return ret;
735 }
736 
737 static struct llist_node *llist_nodes_reverse(struct llist_node *llnode)
738 {
739 	struct llist_node *next, *tail = NULL;
740 
741 	while (llnode) {
742 		next = llnode->next;
743 		llnode->next = tail;
744 		tail = llnode;
745 		llnode = next;
746 	}
747 
748 	return tail;
749 }
750 
751 static void ghes_proc_in_irq(struct irq_work *irq_work)
752 {
753 	struct llist_node *llnode, *next;
754 	struct ghes_estatus_node *estatus_node;
755 	struct acpi_hest_generic *generic;
756 	struct acpi_generic_status *estatus;
757 	u32 len, node_len;
758 
759 	llnode = llist_del_all(&ghes_estatus_llist);
760 	/*
761 	 * Because the time order of estatus in list is reversed,
762 	 * revert it back to proper order.
763 	 */
764 	llnode = llist_nodes_reverse(llnode);
765 	while (llnode) {
766 		next = llnode->next;
767 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
768 					   llnode);
769 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
770 		len = cper_estatus_len(estatus);
771 		node_len = GHES_ESTATUS_NODE_LEN(len);
772 		ghes_do_proc(estatus_node->ghes, estatus);
773 		if (!ghes_estatus_cached(estatus)) {
774 			generic = estatus_node->generic;
775 			if (ghes_print_estatus(NULL, generic, estatus))
776 				ghes_estatus_cache_add(generic, estatus);
777 		}
778 		gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
779 			      node_len);
780 		llnode = next;
781 	}
782 }
783 
784 static void ghes_print_queued_estatus(void)
785 {
786 	struct llist_node *llnode;
787 	struct ghes_estatus_node *estatus_node;
788 	struct acpi_hest_generic *generic;
789 	struct acpi_generic_status *estatus;
790 	u32 len, node_len;
791 
792 	llnode = llist_del_all(&ghes_estatus_llist);
793 	/*
794 	 * Because the time order of estatus in list is reversed,
795 	 * revert it back to proper order.
796 	 */
797 	llnode = llist_nodes_reverse(llnode);
798 	while (llnode) {
799 		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
800 					   llnode);
801 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
802 		len = cper_estatus_len(estatus);
803 		node_len = GHES_ESTATUS_NODE_LEN(len);
804 		generic = estatus_node->generic;
805 		ghes_print_estatus(NULL, generic, estatus);
806 		llnode = llnode->next;
807 	}
808 }
809 
810 static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
811 {
812 	struct ghes *ghes, *ghes_global = NULL;
813 	int sev, sev_global = -1;
814 	int ret = NMI_DONE;
815 
816 	raw_spin_lock(&ghes_nmi_lock);
817 	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
818 		if (ghes_read_estatus(ghes, 1)) {
819 			ghes_clear_estatus(ghes);
820 			continue;
821 		}
822 		sev = ghes_severity(ghes->estatus->error_severity);
823 		if (sev > sev_global) {
824 			sev_global = sev;
825 			ghes_global = ghes;
826 		}
827 		ret = NMI_HANDLED;
828 	}
829 
830 	if (ret == NMI_DONE)
831 		goto out;
832 
833 	if (sev_global >= GHES_SEV_PANIC) {
834 		oops_begin();
835 		ghes_print_queued_estatus();
836 		__ghes_print_estatus(KERN_EMERG, ghes_global->generic,
837 				     ghes_global->estatus);
838 		/* reboot to log the error! */
839 		if (panic_timeout == 0)
840 			panic_timeout = ghes_panic_timeout;
841 		panic("Fatal hardware error!");
842 	}
843 
844 	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
845 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
846 		u32 len, node_len;
847 		struct ghes_estatus_node *estatus_node;
848 		struct acpi_generic_status *estatus;
849 #endif
850 		if (!(ghes->flags & GHES_TO_CLEAR))
851 			continue;
852 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
853 		if (ghes_estatus_cached(ghes->estatus))
854 			goto next;
855 		/* Save estatus for further processing in IRQ context */
856 		len = cper_estatus_len(ghes->estatus);
857 		node_len = GHES_ESTATUS_NODE_LEN(len);
858 		estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
859 						      node_len);
860 		if (estatus_node) {
861 			estatus_node->ghes = ghes;
862 			estatus_node->generic = ghes->generic;
863 			estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
864 			memcpy(estatus, ghes->estatus, len);
865 			llist_add(&estatus_node->llnode, &ghes_estatus_llist);
866 		}
867 next:
868 #endif
869 		ghes_clear_estatus(ghes);
870 	}
871 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
872 	irq_work_queue(&ghes_proc_irq_work);
873 #endif
874 
875 out:
876 	raw_spin_unlock(&ghes_nmi_lock);
877 	return ret;
878 }
879 
880 static struct notifier_block ghes_notifier_sci = {
881 	.notifier_call = ghes_notify_sci,
882 };
883 
884 static unsigned long ghes_esource_prealloc_size(
885 	const struct acpi_hest_generic *generic)
886 {
887 	unsigned long block_length, prealloc_records, prealloc_size;
888 
889 	block_length = min_t(unsigned long, generic->error_block_length,
890 			     GHES_ESTATUS_MAX_SIZE);
891 	prealloc_records = max_t(unsigned long,
892 				 generic->records_to_preallocate, 1);
893 	prealloc_size = min_t(unsigned long, block_length * prealloc_records,
894 			      GHES_ESOURCE_PREALLOC_MAX_SIZE);
895 
896 	return prealloc_size;
897 }
898 
899 static int ghes_probe(struct platform_device *ghes_dev)
900 {
901 	struct acpi_hest_generic *generic;
902 	struct ghes *ghes = NULL;
903 	unsigned long len;
904 	int rc = -EINVAL;
905 
906 	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
907 	if (!generic->enabled)
908 		return -ENODEV;
909 
910 	switch (generic->notify.type) {
911 	case ACPI_HEST_NOTIFY_POLLED:
912 	case ACPI_HEST_NOTIFY_EXTERNAL:
913 	case ACPI_HEST_NOTIFY_SCI:
914 	case ACPI_HEST_NOTIFY_NMI:
915 		break;
916 	case ACPI_HEST_NOTIFY_LOCAL:
917 		pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
918 			   generic->header.source_id);
919 		goto err;
920 	default:
921 		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
922 			   generic->notify.type, generic->header.source_id);
923 		goto err;
924 	}
925 
926 	rc = -EIO;
927 	if (generic->error_block_length <
928 	    sizeof(struct acpi_generic_status)) {
929 		pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
930 			   generic->error_block_length,
931 			   generic->header.source_id);
932 		goto err;
933 	}
934 	ghes = ghes_new(generic);
935 	if (IS_ERR(ghes)) {
936 		rc = PTR_ERR(ghes);
937 		ghes = NULL;
938 		goto err;
939 	}
940 
941 	rc = ghes_edac_register(ghes, &ghes_dev->dev);
942 	if (rc < 0)
943 		goto err;
944 
945 	switch (generic->notify.type) {
946 	case ACPI_HEST_NOTIFY_POLLED:
947 		ghes->timer.function = ghes_poll_func;
948 		ghes->timer.data = (unsigned long)ghes;
949 		init_timer_deferrable(&ghes->timer);
950 		ghes_add_timer(ghes);
951 		break;
952 	case ACPI_HEST_NOTIFY_EXTERNAL:
953 		/* External interrupt vector is GSI */
954 		rc = acpi_gsi_to_irq(generic->notify.vector, &ghes->irq);
955 		if (rc) {
956 			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
957 			       generic->header.source_id);
958 			goto err_edac_unreg;
959 		}
960 		rc = request_irq(ghes->irq, ghes_irq_func, 0, "GHES IRQ", ghes);
961 		if (rc) {
962 			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
963 			       generic->header.source_id);
964 			goto err_edac_unreg;
965 		}
966 		break;
967 	case ACPI_HEST_NOTIFY_SCI:
968 		mutex_lock(&ghes_list_mutex);
969 		if (list_empty(&ghes_sci))
970 			register_acpi_hed_notifier(&ghes_notifier_sci);
971 		list_add_rcu(&ghes->list, &ghes_sci);
972 		mutex_unlock(&ghes_list_mutex);
973 		break;
974 	case ACPI_HEST_NOTIFY_NMI:
975 		len = ghes_esource_prealloc_size(generic);
976 		ghes_estatus_pool_expand(len);
977 		mutex_lock(&ghes_list_mutex);
978 		if (list_empty(&ghes_nmi))
979 			register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0,
980 						"ghes");
981 		list_add_rcu(&ghes->list, &ghes_nmi);
982 		mutex_unlock(&ghes_list_mutex);
983 		break;
984 	default:
985 		BUG();
986 	}
987 	platform_set_drvdata(ghes_dev, ghes);
988 
989 	return 0;
990 err_edac_unreg:
991 	ghes_edac_unregister(ghes);
992 err:
993 	if (ghes) {
994 		ghes_fini(ghes);
995 		kfree(ghes);
996 	}
997 	return rc;
998 }
999 
1000 static int ghes_remove(struct platform_device *ghes_dev)
1001 {
1002 	struct ghes *ghes;
1003 	struct acpi_hest_generic *generic;
1004 	unsigned long len;
1005 
1006 	ghes = platform_get_drvdata(ghes_dev);
1007 	generic = ghes->generic;
1008 
1009 	ghes->flags |= GHES_EXITING;
1010 	switch (generic->notify.type) {
1011 	case ACPI_HEST_NOTIFY_POLLED:
1012 		del_timer_sync(&ghes->timer);
1013 		break;
1014 	case ACPI_HEST_NOTIFY_EXTERNAL:
1015 		free_irq(ghes->irq, ghes);
1016 		break;
1017 	case ACPI_HEST_NOTIFY_SCI:
1018 		mutex_lock(&ghes_list_mutex);
1019 		list_del_rcu(&ghes->list);
1020 		if (list_empty(&ghes_sci))
1021 			unregister_acpi_hed_notifier(&ghes_notifier_sci);
1022 		mutex_unlock(&ghes_list_mutex);
1023 		break;
1024 	case ACPI_HEST_NOTIFY_NMI:
1025 		mutex_lock(&ghes_list_mutex);
1026 		list_del_rcu(&ghes->list);
1027 		if (list_empty(&ghes_nmi))
1028 			unregister_nmi_handler(NMI_LOCAL, "ghes");
1029 		mutex_unlock(&ghes_list_mutex);
1030 		/*
1031 		 * To synchronize with NMI handler, ghes can only be
1032 		 * freed after NMI handler finishes.
1033 		 */
1034 		synchronize_rcu();
1035 		len = ghes_esource_prealloc_size(generic);
1036 		ghes_estatus_pool_shrink(len);
1037 		break;
1038 	default:
1039 		BUG();
1040 		break;
1041 	}
1042 
1043 	ghes_fini(ghes);
1044 
1045 	ghes_edac_unregister(ghes);
1046 
1047 	kfree(ghes);
1048 
1049 	platform_set_drvdata(ghes_dev, NULL);
1050 
1051 	return 0;
1052 }
1053 
1054 static struct platform_driver ghes_platform_driver = {
1055 	.driver		= {
1056 		.name	= "GHES",
1057 		.owner	= THIS_MODULE,
1058 	},
1059 	.probe		= ghes_probe,
1060 	.remove		= ghes_remove,
1061 };
1062 
1063 static int __init ghes_init(void)
1064 {
1065 	int rc;
1066 
1067 	if (acpi_disabled)
1068 		return -ENODEV;
1069 
1070 	if (hest_disable) {
1071 		pr_info(GHES_PFX "HEST is not enabled!\n");
1072 		return -EINVAL;
1073 	}
1074 
1075 	if (ghes_disable) {
1076 		pr_info(GHES_PFX "GHES is not enabled!\n");
1077 		return -EINVAL;
1078 	}
1079 
1080 	init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
1081 
1082 	rc = ghes_ioremap_init();
1083 	if (rc)
1084 		goto err;
1085 
1086 	rc = ghes_estatus_pool_init();
1087 	if (rc)
1088 		goto err_ioremap_exit;
1089 
1090 	rc = ghes_estatus_pool_expand(GHES_ESTATUS_CACHE_AVG_SIZE *
1091 				      GHES_ESTATUS_CACHE_ALLOCED_MAX);
1092 	if (rc)
1093 		goto err_pool_exit;
1094 
1095 	rc = platform_driver_register(&ghes_platform_driver);
1096 	if (rc)
1097 		goto err_pool_exit;
1098 
1099 	rc = apei_osc_setup();
1100 	if (rc == 0 && osc_sb_apei_support_acked)
1101 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1102 	else if (rc == 0 && !osc_sb_apei_support_acked)
1103 		pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1104 	else if (rc && osc_sb_apei_support_acked)
1105 		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1106 	else
1107 		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1108 
1109 	return 0;
1110 err_pool_exit:
1111 	ghes_estatus_pool_exit();
1112 err_ioremap_exit:
1113 	ghes_ioremap_exit();
1114 err:
1115 	return rc;
1116 }
1117 
1118 static void __exit ghes_exit(void)
1119 {
1120 	platform_driver_unregister(&ghes_platform_driver);
1121 	ghes_estatus_pool_exit();
1122 	ghes_ioremap_exit();
1123 }
1124 
1125 module_init(ghes_init);
1126 module_exit(ghes_exit);
1127 
1128 MODULE_AUTHOR("Huang Ying");
1129 MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1130 MODULE_LICENSE("GPL");
1131 MODULE_ALIAS("platform:GHES");
1132