ghes.c revision 81e88fdc432a1552401d6e91a984dcccce72b8dc 
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 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 <acpi/apei.h>
46#include <acpi/atomicio.h>
47#include <acpi/hed.h>
48#include <asm/mce.h>
49#include <asm/tlbflush.h>
50
51#include "apei-internal.h"
52
53#define GHES_PFX	"GHES: "
54
55#define GHES_ESTATUS_MAX_SIZE		65536
56
57/*
58 * One struct ghes is created for each generic hardware error source.
59 * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
60 * handler.
61 *
62 * estatus: memory buffer for error status block, allocated during
63 * HEST parsing.
64 */
65#define GHES_TO_CLEAR		0x0001
66#define GHES_EXITING		0x0002
67
68struct ghes {
69	struct acpi_hest_generic *generic;
70	struct acpi_hest_generic_status *estatus;
71	u64 buffer_paddr;
72	unsigned long flags;
73	union {
74		struct list_head list;
75		struct timer_list timer;
76		unsigned int irq;
77	};
78};
79
80static int ghes_panic_timeout	__read_mostly = 30;
81
82/*
83 * All error sources notified with SCI shares one notifier function,
84 * so they need to be linked and checked one by one.  This is applied
85 * to NMI too.
86 *
87 * RCU is used for these lists, so ghes_list_mutex is only used for
88 * list changing, not for traversing.
89 */
90static LIST_HEAD(ghes_sci);
91static LIST_HEAD(ghes_nmi);
92static DEFINE_MUTEX(ghes_list_mutex);
93
94/*
95 * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
96 * mutual exclusion.
97 */
98static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
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 NMI context, the other for
109 * IRQ/PROCESS context
110 */
111#define GHES_IOREMAP_PAGES		2
112#define GHES_IOREMAP_NMI_PAGE(base)	(base)
113#define GHES_IOREMAP_IRQ_PAGE(base)	((base) + PAGE_SIZE)
114
115/* virtual memory area for atomic ioremap */
116static struct vm_struct *ghes_ioremap_area;
117/*
118 * These 2 spinlock is used to prevent atomic ioremap virtual memory
119 * area from being mapped simultaneously.
120 */
121static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
122static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
123
124static int ghes_ioremap_init(void)
125{
126	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
127		VM_IOREMAP, VMALLOC_START, VMALLOC_END);
128	if (!ghes_ioremap_area) {
129		pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
130		return -ENOMEM;
131	}
132
133	return 0;
134}
135
136static void ghes_ioremap_exit(void)
137{
138	free_vm_area(ghes_ioremap_area);
139}
140
141static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
142{
143	unsigned long vaddr;
144
145	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
146	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
147			   pfn << PAGE_SHIFT, PAGE_KERNEL);
148
149	return (void __iomem *)vaddr;
150}
151
152static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
153{
154	unsigned long vaddr;
155
156	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
157	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
158			   pfn << PAGE_SHIFT, PAGE_KERNEL);
159
160	return (void __iomem *)vaddr;
161}
162
163static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
164{
165	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
166	void *base = ghes_ioremap_area->addr;
167
168	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
169	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
170	__flush_tlb_one(vaddr);
171}
172
173static void ghes_iounmap_irq(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_IRQ_PAGE(base));
179	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
180	__flush_tlb_one(vaddr);
181}
182
183static struct ghes *ghes_new(struct acpi_hest_generic *generic)
184{
185	struct ghes *ghes;
186	unsigned int error_block_length;
187	int rc;
188
189	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
190	if (!ghes)
191		return ERR_PTR(-ENOMEM);
192	ghes->generic = generic;
193	rc = acpi_pre_map_gar(&generic->error_status_address);
194	if (rc)
195		goto err_free;
196	error_block_length = generic->error_block_length;
197	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
198		pr_warning(FW_WARN GHES_PFX
199			   "Error status block length is too long: %u for "
200			   "generic hardware error source: %d.\n",
201			   error_block_length, generic->header.source_id);
202		error_block_length = GHES_ESTATUS_MAX_SIZE;
203	}
204	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
205	if (!ghes->estatus) {
206		rc = -ENOMEM;
207		goto err_unmap;
208	}
209
210	return ghes;
211
212err_unmap:
213	acpi_post_unmap_gar(&generic->error_status_address);
214err_free:
215	kfree(ghes);
216	return ERR_PTR(rc);
217}
218
219static void ghes_fini(struct ghes *ghes)
220{
221	kfree(ghes->estatus);
222	acpi_post_unmap_gar(&ghes->generic->error_status_address);
223}
224
225enum {
226	GHES_SEV_NO = 0x0,
227	GHES_SEV_CORRECTED = 0x1,
228	GHES_SEV_RECOVERABLE = 0x2,
229	GHES_SEV_PANIC = 0x3,
230};
231
232static inline int ghes_severity(int severity)
233{
234	switch (severity) {
235	case CPER_SEV_INFORMATIONAL:
236		return GHES_SEV_NO;
237	case CPER_SEV_CORRECTED:
238		return GHES_SEV_CORRECTED;
239	case CPER_SEV_RECOVERABLE:
240		return GHES_SEV_RECOVERABLE;
241	case CPER_SEV_FATAL:
242		return GHES_SEV_PANIC;
243	default:
244		/* Unkown, go panic */
245		return GHES_SEV_PANIC;
246	}
247}
248
249static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
250				  int from_phys)
251{
252	void __iomem *vaddr;
253	unsigned long flags = 0;
254	int in_nmi = in_nmi();
255	u64 offset;
256	u32 trunk;
257
258	while (len > 0) {
259		offset = paddr - (paddr & PAGE_MASK);
260		if (in_nmi) {
261			raw_spin_lock(&ghes_ioremap_lock_nmi);
262			vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
263		} else {
264			spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
265			vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
266		}
267		trunk = PAGE_SIZE - offset;
268		trunk = min(trunk, len);
269		if (from_phys)
270			memcpy_fromio(buffer, vaddr + offset, trunk);
271		else
272			memcpy_toio(vaddr + offset, buffer, trunk);
273		len -= trunk;
274		paddr += trunk;
275		buffer += trunk;
276		if (in_nmi) {
277			ghes_iounmap_nmi(vaddr);
278			raw_spin_unlock(&ghes_ioremap_lock_nmi);
279		} else {
280			ghes_iounmap_irq(vaddr);
281			spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
282		}
283	}
284}
285
286static int ghes_read_estatus(struct ghes *ghes, int silent)
287{
288	struct acpi_hest_generic *g = ghes->generic;
289	u64 buf_paddr;
290	u32 len;
291	int rc;
292
293	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
294	if (rc) {
295		if (!silent && printk_ratelimit())
296			pr_warning(FW_WARN GHES_PFX
297"Failed to read error status block address for hardware error source: %d.\n",
298				   g->header.source_id);
299		return -EIO;
300	}
301	if (!buf_paddr)
302		return -ENOENT;
303
304	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
305			      sizeof(*ghes->estatus), 1);
306	if (!ghes->estatus->block_status)
307		return -ENOENT;
308
309	ghes->buffer_paddr = buf_paddr;
310	ghes->flags |= GHES_TO_CLEAR;
311
312	rc = -EIO;
313	len = apei_estatus_len(ghes->estatus);
314	if (len < sizeof(*ghes->estatus))
315		goto err_read_block;
316	if (len > ghes->generic->error_block_length)
317		goto err_read_block;
318	if (apei_estatus_check_header(ghes->estatus))
319		goto err_read_block;
320	ghes_copy_tofrom_phys(ghes->estatus + 1,
321			      buf_paddr + sizeof(*ghes->estatus),
322			      len - sizeof(*ghes->estatus), 1);
323	if (apei_estatus_check(ghes->estatus))
324		goto err_read_block;
325	rc = 0;
326
327err_read_block:
328	if (rc && !silent && printk_ratelimit())
329		pr_warning(FW_WARN GHES_PFX
330			   "Failed to read error status block!\n");
331	return rc;
332}
333
334static void ghes_clear_estatus(struct ghes *ghes)
335{
336	ghes->estatus->block_status = 0;
337	if (!(ghes->flags & GHES_TO_CLEAR))
338		return;
339	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
340			      sizeof(ghes->estatus->block_status), 0);
341	ghes->flags &= ~GHES_TO_CLEAR;
342}
343
344static void ghes_do_proc(struct ghes *ghes)
345{
346	int sev, processed = 0;
347	struct acpi_hest_generic_data *gdata;
348
349	sev = ghes_severity(ghes->estatus->error_severity);
350	apei_estatus_for_each_section(ghes->estatus, gdata) {
351#ifdef CONFIG_X86_MCE
352		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
353				 CPER_SEC_PLATFORM_MEM)) {
354			apei_mce_report_mem_error(
355				sev == GHES_SEV_CORRECTED,
356				(struct cper_sec_mem_err *)(gdata+1));
357			processed = 1;
358		}
359#endif
360	}
361}
362
363static void ghes_print_estatus(const char *pfx, struct ghes *ghes)
364{
365	/* Not more than 2 messages every 5 seconds */
366	static DEFINE_RATELIMIT_STATE(ratelimit, 5*HZ, 2);
367
368	if (pfx == NULL) {
369		if (ghes_severity(ghes->estatus->error_severity) <=
370		    GHES_SEV_CORRECTED)
371			pfx = KERN_WARNING HW_ERR;
372		else
373			pfx = KERN_ERR HW_ERR;
374	}
375	if (__ratelimit(&ratelimit)) {
376		printk(
377	"%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
378	pfx, ghes->generic->header.source_id);
379		apei_estatus_print(pfx, ghes->estatus);
380	}
381}
382
383static int ghes_proc(struct ghes *ghes)
384{
385	int rc;
386
387	rc = ghes_read_estatus(ghes, 0);
388	if (rc)
389		goto out;
390	ghes_print_estatus(NULL, ghes);
391	ghes_do_proc(ghes);
392
393out:
394	ghes_clear_estatus(ghes);
395	return 0;
396}
397
398static void ghes_add_timer(struct ghes *ghes)
399{
400	struct acpi_hest_generic *g = ghes->generic;
401	unsigned long expire;
402
403	if (!g->notify.poll_interval) {
404		pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
405			   g->header.source_id);
406		return;
407	}
408	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
409	ghes->timer.expires = round_jiffies_relative(expire);
410	add_timer(&ghes->timer);
411}
412
413static void ghes_poll_func(unsigned long data)
414{
415	struct ghes *ghes = (void *)data;
416
417	ghes_proc(ghes);
418	if (!(ghes->flags & GHES_EXITING))
419		ghes_add_timer(ghes);
420}
421
422static irqreturn_t ghes_irq_func(int irq, void *data)
423{
424	struct ghes *ghes = data;
425	int rc;
426
427	rc = ghes_proc(ghes);
428	if (rc)
429		return IRQ_NONE;
430
431	return IRQ_HANDLED;
432}
433
434static int ghes_notify_sci(struct notifier_block *this,
435				  unsigned long event, void *data)
436{
437	struct ghes *ghes;
438	int ret = NOTIFY_DONE;
439
440	rcu_read_lock();
441	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
442		if (!ghes_proc(ghes))
443			ret = NOTIFY_OK;
444	}
445	rcu_read_unlock();
446
447	return ret;
448}
449
450static int ghes_notify_nmi(struct notifier_block *this,
451				  unsigned long cmd, void *data)
452{
453	struct ghes *ghes, *ghes_global = NULL;
454	int sev, sev_global = -1;
455	int ret = NOTIFY_DONE;
456
457	if (cmd != DIE_NMI)
458		return ret;
459
460	raw_spin_lock(&ghes_nmi_lock);
461	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
462		if (ghes_read_estatus(ghes, 1)) {
463			ghes_clear_estatus(ghes);
464			continue;
465		}
466		sev = ghes_severity(ghes->estatus->error_severity);
467		if (sev > sev_global) {
468			sev_global = sev;
469			ghes_global = ghes;
470		}
471		ret = NOTIFY_STOP;
472	}
473
474	if (ret == NOTIFY_DONE)
475		goto out;
476
477	if (sev_global >= GHES_SEV_PANIC) {
478		oops_begin();
479		ghes_print_estatus(KERN_EMERG HW_ERR, ghes_global);
480		/* reboot to log the error! */
481		if (panic_timeout == 0)
482			panic_timeout = ghes_panic_timeout;
483		panic("Fatal hardware error!");
484	}
485
486	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
487		if (!(ghes->flags & GHES_TO_CLEAR))
488			continue;
489		/* Do not print estatus because printk is not NMI safe */
490		ghes_do_proc(ghes);
491		ghes_clear_estatus(ghes);
492	}
493
494out:
495	raw_spin_unlock(&ghes_nmi_lock);
496	return ret;
497}
498
499static struct notifier_block ghes_notifier_sci = {
500	.notifier_call = ghes_notify_sci,
501};
502
503static struct notifier_block ghes_notifier_nmi = {
504	.notifier_call = ghes_notify_nmi,
505};
506
507static int __devinit ghes_probe(struct platform_device *ghes_dev)
508{
509	struct acpi_hest_generic *generic;
510	struct ghes *ghes = NULL;
511	int rc = -EINVAL;
512
513	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
514	if (!generic->enabled)
515		return -ENODEV;
516
517	switch (generic->notify.type) {
518	case ACPI_HEST_NOTIFY_POLLED:
519	case ACPI_HEST_NOTIFY_EXTERNAL:
520	case ACPI_HEST_NOTIFY_SCI:
521	case ACPI_HEST_NOTIFY_NMI:
522		break;
523	case ACPI_HEST_NOTIFY_LOCAL:
524		pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
525			   generic->header.source_id);
526		goto err;
527	default:
528		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
529			   generic->notify.type, generic->header.source_id);
530		goto err;
531	}
532
533	rc = -EIO;
534	if (generic->error_block_length <
535	    sizeof(struct acpi_hest_generic_status)) {
536		pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
537			   generic->error_block_length,
538			   generic->header.source_id);
539		goto err;
540	}
541	ghes = ghes_new(generic);
542	if (IS_ERR(ghes)) {
543		rc = PTR_ERR(ghes);
544		ghes = NULL;
545		goto err;
546	}
547	switch (generic->notify.type) {
548	case ACPI_HEST_NOTIFY_POLLED:
549		ghes->timer.function = ghes_poll_func;
550		ghes->timer.data = (unsigned long)ghes;
551		init_timer_deferrable(&ghes->timer);
552		ghes_add_timer(ghes);
553		break;
554	case ACPI_HEST_NOTIFY_EXTERNAL:
555		/* External interrupt vector is GSI */
556		if (acpi_gsi_to_irq(generic->notify.vector, &ghes->irq)) {
557			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
558			       generic->header.source_id);
559			goto err;
560		}
561		if (request_irq(ghes->irq, ghes_irq_func,
562				0, "GHES IRQ", ghes)) {
563			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
564			       generic->header.source_id);
565			goto err;
566		}
567		break;
568	case ACPI_HEST_NOTIFY_SCI:
569		mutex_lock(&ghes_list_mutex);
570		if (list_empty(&ghes_sci))
571			register_acpi_hed_notifier(&ghes_notifier_sci);
572		list_add_rcu(&ghes->list, &ghes_sci);
573		mutex_unlock(&ghes_list_mutex);
574		break;
575	case ACPI_HEST_NOTIFY_NMI:
576		mutex_lock(&ghes_list_mutex);
577		if (list_empty(&ghes_nmi))
578			register_die_notifier(&ghes_notifier_nmi);
579		list_add_rcu(&ghes->list, &ghes_nmi);
580		mutex_unlock(&ghes_list_mutex);
581		break;
582	default:
583		BUG();
584	}
585	platform_set_drvdata(ghes_dev, ghes);
586
587	return 0;
588err:
589	if (ghes) {
590		ghes_fini(ghes);
591		kfree(ghes);
592	}
593	return rc;
594}
595
596static int __devexit ghes_remove(struct platform_device *ghes_dev)
597{
598	struct ghes *ghes;
599	struct acpi_hest_generic *generic;
600
601	ghes = platform_get_drvdata(ghes_dev);
602	generic = ghes->generic;
603
604	ghes->flags |= GHES_EXITING;
605	switch (generic->notify.type) {
606	case ACPI_HEST_NOTIFY_POLLED:
607		del_timer_sync(&ghes->timer);
608		break;
609	case ACPI_HEST_NOTIFY_EXTERNAL:
610		free_irq(ghes->irq, ghes);
611		break;
612	case ACPI_HEST_NOTIFY_SCI:
613		mutex_lock(&ghes_list_mutex);
614		list_del_rcu(&ghes->list);
615		if (list_empty(&ghes_sci))
616			unregister_acpi_hed_notifier(&ghes_notifier_sci);
617		mutex_unlock(&ghes_list_mutex);
618		break;
619	case ACPI_HEST_NOTIFY_NMI:
620		mutex_lock(&ghes_list_mutex);
621		list_del_rcu(&ghes->list);
622		if (list_empty(&ghes_nmi))
623			unregister_die_notifier(&ghes_notifier_nmi);
624		mutex_unlock(&ghes_list_mutex);
625		/*
626		 * To synchronize with NMI handler, ghes can only be
627		 * freed after NMI handler finishes.
628		 */
629		synchronize_rcu();
630		break;
631	default:
632		BUG();
633		break;
634	}
635
636	ghes_fini(ghes);
637	kfree(ghes);
638
639	platform_set_drvdata(ghes_dev, NULL);
640
641	return 0;
642}
643
644static struct platform_driver ghes_platform_driver = {
645	.driver		= {
646		.name	= "GHES",
647		.owner	= THIS_MODULE,
648	},
649	.probe		= ghes_probe,
650	.remove		= ghes_remove,
651};
652
653static int __init ghes_init(void)
654{
655	int rc;
656
657	if (acpi_disabled)
658		return -ENODEV;
659
660	if (hest_disable) {
661		pr_info(GHES_PFX "HEST is not enabled!\n");
662		return -EINVAL;
663	}
664
665	rc = ghes_ioremap_init();
666	if (rc)
667		goto err;
668
669	rc = platform_driver_register(&ghes_platform_driver);
670	if (rc)
671		goto err_ioremap_exit;
672
673	return 0;
674err_ioremap_exit:
675	ghes_ioremap_exit();
676err:
677	return rc;
678}
679
680static void __exit ghes_exit(void)
681{
682	platform_driver_unregister(&ghes_platform_driver);
683	ghes_ioremap_exit();
684}
685
686module_init(ghes_init);
687module_exit(ghes_exit);
688
689MODULE_AUTHOR("Huang Ying");
690MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
691MODULE_LICENSE("GPL");
692MODULE_ALIAS("platform:GHES");
693