Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
/*
 * APEI Generic Hardware Error Source support
 *
 * Generic Hardware Error Source provides a way to report platform
 * hardware errors (such as that from chipset). It works in so called
 * "Firmware First" mode, that is, hardware errors are reported to
 * firmware firstly, then reported to Linux by firmware. This way,
 * some non-standard hardware error registers or non-standard hardware
 * link can be checked by firmware to produce more hardware error
 * information for Linux.
 *
 * For more information about Generic Hardware Error Source, please
 * refer to ACPI Specification version 4.0, section 17.3.2.6
 *
 * Copyright 2010 Intel Corp.
 *   Author: Huang Ying <ying.huang@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/cper.h>
#include <linux/kdebug.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/ratelimit.h>
#include <linux/vmalloc.h>
#include <acpi/apei.h>
#include <acpi/atomicio.h>
#include <acpi/hed.h>
#include <asm/mce.h>
#include <asm/tlbflush.h>

#include "apei-internal.h"

#define GHES_PFX	"GHES: "

#define GHES_ESTATUS_MAX_SIZE		65536

/*
 * One struct ghes is created for each generic hardware error source.
 * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
 * handler.
 *
 * estatus: memory buffer for error status block, allocated during
 * HEST parsing.
 */
#define GHES_TO_CLEAR		0x0001
#define GHES_EXITING		0x0002

struct ghes {
	struct acpi_hest_generic *generic;
	struct acpi_hest_generic_status *estatus;
	u64 buffer_paddr;
	unsigned long flags;
	union {
		struct list_head list;
		struct timer_list timer;
		unsigned int irq;
	};
};

static int ghes_panic_timeout	__read_mostly = 30;

/*
 * All error sources notified with SCI shares one notifier function,
 * so they need to be linked and checked one by one.  This is applied
 * to NMI too.
 *
 * RCU is used for these lists, so ghes_list_mutex is only used for
 * list changing, not for traversing.
 */
static LIST_HEAD(ghes_sci);
static LIST_HEAD(ghes_nmi);
static DEFINE_MUTEX(ghes_list_mutex);

/*
 * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
 * mutual exclusion.
 */
static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);

/*
 * Because the memory area used to transfer hardware error information
 * from BIOS to Linux can be determined only in NMI, IRQ or timer
 * handler, but general ioremap can not be used in atomic context, so
 * a special version of atomic ioremap is implemented for that.
 */

/*
 * Two virtual pages are used, one for NMI context, the other for
 * IRQ/PROCESS context
 */
#define GHES_IOREMAP_PAGES		2
#define GHES_IOREMAP_NMI_PAGE(base)	(base)
#define GHES_IOREMAP_IRQ_PAGE(base)	((base) + PAGE_SIZE)

/* virtual memory area for atomic ioremap */
static struct vm_struct *ghes_ioremap_area;
/*
 * These 2 spinlock is used to prevent atomic ioremap virtual memory
 * area from being mapped simultaneously.
 */
static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);

static int ghes_ioremap_init(void)
{
	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
		VM_IOREMAP, VMALLOC_START, VMALLOC_END);
	if (!ghes_ioremap_area) {
		pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
		return -ENOMEM;
	}

	return 0;
}

static void ghes_ioremap_exit(void)
{
	free_vm_area(ghes_ioremap_area);
}

static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
{
	unsigned long vaddr;

	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
			   pfn << PAGE_SHIFT, PAGE_KERNEL);

	return (void __iomem *)vaddr;
}

static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
{
	unsigned long vaddr;

	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
			   pfn << PAGE_SHIFT, PAGE_KERNEL);

	return (void __iomem *)vaddr;
}

static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
{
	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
	void *base = ghes_ioremap_area->addr;

	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
	__flush_tlb_one(vaddr);
}

static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
{
	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
	void *base = ghes_ioremap_area->addr;

	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
	__flush_tlb_one(vaddr);
}

static struct ghes *ghes_new(struct acpi_hest_generic *generic)
{
	struct ghes *ghes;
	unsigned int error_block_length;
	int rc;

	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
	if (!ghes)
		return ERR_PTR(-ENOMEM);
	ghes->generic = generic;
	rc = acpi_pre_map_gar(&generic->error_status_address);
	if (rc)
		goto err_free;
	error_block_length = generic->error_block_length;
	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
		pr_warning(FW_WARN GHES_PFX
			   "Error status block length is too long: %u for "
			   "generic hardware error source: %d.\n",
			   error_block_length, generic->header.source_id);
		error_block_length = GHES_ESTATUS_MAX_SIZE;
	}
	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
	if (!ghes->estatus) {
		rc = -ENOMEM;
		goto err_unmap;
	}

	return ghes;

err_unmap:
	acpi_post_unmap_gar(&generic->error_status_address);
err_free:
	kfree(ghes);
	return ERR_PTR(rc);
}

static void ghes_fini(struct ghes *ghes)
{
	kfree(ghes->estatus);
	acpi_post_unmap_gar(&ghes->generic->error_status_address);
}

enum {
	GHES_SEV_NO = 0x0,
	GHES_SEV_CORRECTED = 0x1,
	GHES_SEV_RECOVERABLE = 0x2,
	GHES_SEV_PANIC = 0x3,
};

static inline int ghes_severity(int severity)
{
	switch (severity) {
	case CPER_SEV_INFORMATIONAL:
		return GHES_SEV_NO;
	case CPER_SEV_CORRECTED:
		return GHES_SEV_CORRECTED;
	case CPER_SEV_RECOVERABLE:
		return GHES_SEV_RECOVERABLE;
	case CPER_SEV_FATAL:
		return GHES_SEV_PANIC;
	default:
		/* Unknown, go panic */
		return GHES_SEV_PANIC;
	}
}

static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
				  int from_phys)
{
	void __iomem *vaddr;
	unsigned long flags = 0;
	int in_nmi = in_nmi();
	u64 offset;
	u32 trunk;

	while (len > 0) {
		offset = paddr - (paddr & PAGE_MASK);
		if (in_nmi) {
			raw_spin_lock(&ghes_ioremap_lock_nmi);
			vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
		} else {
			spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
			vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
		}
		trunk = PAGE_SIZE - offset;
		trunk = min(trunk, len);
		if (from_phys)
			memcpy_fromio(buffer, vaddr + offset, trunk);
		else
			memcpy_toio(vaddr + offset, buffer, trunk);
		len -= trunk;
		paddr += trunk;
		buffer += trunk;
		if (in_nmi) {
			ghes_iounmap_nmi(vaddr);
			raw_spin_unlock(&ghes_ioremap_lock_nmi);
		} else {
			ghes_iounmap_irq(vaddr);
			spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
		}
	}
}

static int ghes_read_estatus(struct ghes *ghes, int silent)
{
	struct acpi_hest_generic *g = ghes->generic;
	u64 buf_paddr;
	u32 len;
	int rc;

	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
	if (rc) {
		if (!silent && printk_ratelimit())
			pr_warning(FW_WARN GHES_PFX
"Failed to read error status block address for hardware error source: %d.\n",
				   g->header.source_id);
		return -EIO;
	}
	if (!buf_paddr)
		return -ENOENT;

	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
			      sizeof(*ghes->estatus), 1);
	if (!ghes->estatus->block_status)
		return -ENOENT;

	ghes->buffer_paddr = buf_paddr;
	ghes->flags |= GHES_TO_CLEAR;

	rc = -EIO;
	len = apei_estatus_len(ghes->estatus);
	if (len < sizeof(*ghes->estatus))
		goto err_read_block;
	if (len > ghes->generic->error_block_length)
		goto err_read_block;
	if (apei_estatus_check_header(ghes->estatus))
		goto err_read_block;
	ghes_copy_tofrom_phys(ghes->estatus + 1,
			      buf_paddr + sizeof(*ghes->estatus),
			      len - sizeof(*ghes->estatus), 1);
	if (apei_estatus_check(ghes->estatus))
		goto err_read_block;
	rc = 0;

err_read_block:
	if (rc && !silent && printk_ratelimit())
		pr_warning(FW_WARN GHES_PFX
			   "Failed to read error status block!\n");
	return rc;
}

static void ghes_clear_estatus(struct ghes *ghes)
{
	ghes->estatus->block_status = 0;
	if (!(ghes->flags & GHES_TO_CLEAR))
		return;
	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
			      sizeof(ghes->estatus->block_status), 0);
	ghes->flags &= ~GHES_TO_CLEAR;
}

static void ghes_do_proc(struct ghes *ghes)
{
	int sev, processed = 0;
	struct acpi_hest_generic_data *gdata;

	sev = ghes_severity(ghes->estatus->error_severity);
	apei_estatus_for_each_section(ghes->estatus, gdata) {
#ifdef CONFIG_X86_MCE
		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
				 CPER_SEC_PLATFORM_MEM)) {
			apei_mce_report_mem_error(
				sev == GHES_SEV_CORRECTED,
				(struct cper_sec_mem_err *)(gdata+1));
			processed = 1;
		}
#endif
	}
}

static void ghes_print_estatus(const char *pfx, struct ghes *ghes)
{
	/* Not more than 2 messages every 5 seconds */
	static DEFINE_RATELIMIT_STATE(ratelimit, 5*HZ, 2);

	if (pfx == NULL) {
		if (ghes_severity(ghes->estatus->error_severity) <=
		    GHES_SEV_CORRECTED)
			pfx = KERN_WARNING HW_ERR;
		else
			pfx = KERN_ERR HW_ERR;
	}
	if (__ratelimit(&ratelimit)) {
		printk(
	"%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
	pfx, ghes->generic->header.source_id);
		apei_estatus_print(pfx, ghes->estatus);
	}
}

static int ghes_proc(struct ghes *ghes)
{
	int rc;

	rc = ghes_read_estatus(ghes, 0);
	if (rc)
		goto out;
	ghes_print_estatus(NULL, ghes);
	ghes_do_proc(ghes);

out:
	ghes_clear_estatus(ghes);
	return 0;
}

static void ghes_add_timer(struct ghes *ghes)
{
	struct acpi_hest_generic *g = ghes->generic;
	unsigned long expire;

	if (!g->notify.poll_interval) {
		pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
			   g->header.source_id);
		return;
	}
	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
	ghes->timer.expires = round_jiffies_relative(expire);
	add_timer(&ghes->timer);
}

static void ghes_poll_func(unsigned long data)
{
	struct ghes *ghes = (void *)data;

	ghes_proc(ghes);
	if (!(ghes->flags & GHES_EXITING))
		ghes_add_timer(ghes);
}

static irqreturn_t ghes_irq_func(int irq, void *data)
{
	struct ghes *ghes = data;
	int rc;

	rc = ghes_proc(ghes);
	if (rc)
		return IRQ_NONE;

	return IRQ_HANDLED;
}

static int ghes_notify_sci(struct notifier_block *this,
				  unsigned long event, void *data)
{
	struct ghes *ghes;
	int ret = NOTIFY_DONE;

	rcu_read_lock();
	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
		if (!ghes_proc(ghes))
			ret = NOTIFY_OK;
	}
	rcu_read_unlock();

	return ret;
}

static int ghes_notify_nmi(struct notifier_block *this,
				  unsigned long cmd, void *data)
{
	struct ghes *ghes, *ghes_global = NULL;
	int sev, sev_global = -1;
	int ret = NOTIFY_DONE;

	if (cmd != DIE_NMI)
		return ret;

	raw_spin_lock(&ghes_nmi_lock);
	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
		if (ghes_read_estatus(ghes, 1)) {
			ghes_clear_estatus(ghes);
			continue;
		}
		sev = ghes_severity(ghes->estatus->error_severity);
		if (sev > sev_global) {
			sev_global = sev;
			ghes_global = ghes;
		}
		ret = NOTIFY_STOP;
	}

	if (ret == NOTIFY_DONE)
		goto out;

	if (sev_global >= GHES_SEV_PANIC) {
		oops_begin();
		ghes_print_estatus(KERN_EMERG HW_ERR, ghes_global);
		/* reboot to log the error! */
		if (panic_timeout == 0)
			panic_timeout = ghes_panic_timeout;
		panic("Fatal hardware error!");
	}

	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
		if (!(ghes->flags & GHES_TO_CLEAR))
			continue;
		/* Do not print estatus because printk is not NMI safe */
		ghes_do_proc(ghes);
		ghes_clear_estatus(ghes);
	}

out:
	raw_spin_unlock(&ghes_nmi_lock);
	return ret;
}

static struct notifier_block ghes_notifier_sci = {
	.notifier_call = ghes_notify_sci,
};

static struct notifier_block ghes_notifier_nmi = {
	.notifier_call = ghes_notify_nmi,
};

static int __devinit ghes_probe(struct platform_device *ghes_dev)
{
	struct acpi_hest_generic *generic;
	struct ghes *ghes = NULL;
	int rc = -EINVAL;

	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
	if (!generic->enabled)
		return -ENODEV;

	switch (generic->notify.type) {
	case ACPI_HEST_NOTIFY_POLLED:
	case ACPI_HEST_NOTIFY_EXTERNAL:
	case ACPI_HEST_NOTIFY_SCI:
	case ACPI_HEST_NOTIFY_NMI:
		break;
	case ACPI_HEST_NOTIFY_LOCAL:
		pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
			   generic->header.source_id);
		goto err;
	default:
		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
			   generic->notify.type, generic->header.source_id);
		goto err;
	}

	rc = -EIO;
	if (generic->error_block_length <
	    sizeof(struct acpi_hest_generic_status)) {
		pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
			   generic->error_block_length,
			   generic->header.source_id);
		goto err;
	}
	ghes = ghes_new(generic);
	if (IS_ERR(ghes)) {
		rc = PTR_ERR(ghes);
		ghes = NULL;
		goto err;
	}
	switch (generic->notify.type) {
	case ACPI_HEST_NOTIFY_POLLED:
		ghes->timer.function = ghes_poll_func;
		ghes->timer.data = (unsigned long)ghes;
		init_timer_deferrable(&ghes->timer);
		ghes_add_timer(ghes);
		break;
	case ACPI_HEST_NOTIFY_EXTERNAL:
		/* External interrupt vector is GSI */
		if (acpi_gsi_to_irq(generic->notify.vector, &ghes->irq)) {
			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
			       generic->header.source_id);
			goto err;
		}
		if (request_irq(ghes->irq, ghes_irq_func,
				0, "GHES IRQ", ghes)) {
			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
			       generic->header.source_id);
			goto err;
		}
		break;
	case ACPI_HEST_NOTIFY_SCI:
		mutex_lock(&ghes_list_mutex);
		if (list_empty(&ghes_sci))
			register_acpi_hed_notifier(&ghes_notifier_sci);
		list_add_rcu(&ghes->list, &ghes_sci);
		mutex_unlock(&ghes_list_mutex);
		break;
	case ACPI_HEST_NOTIFY_NMI:
		mutex_lock(&ghes_list_mutex);
		if (list_empty(&ghes_nmi))
			register_die_notifier(&ghes_notifier_nmi);
		list_add_rcu(&ghes->list, &ghes_nmi);
		mutex_unlock(&ghes_list_mutex);
		break;
	default:
		BUG();
	}
	platform_set_drvdata(ghes_dev, ghes);

	return 0;
err:
	if (ghes) {
		ghes_fini(ghes);
		kfree(ghes);
	}
	return rc;
}

static int __devexit ghes_remove(struct platform_device *ghes_dev)
{
	struct ghes *ghes;
	struct acpi_hest_generic *generic;

	ghes = platform_get_drvdata(ghes_dev);
	generic = ghes->generic;

	ghes->flags |= GHES_EXITING;
	switch (generic->notify.type) {
	case ACPI_HEST_NOTIFY_POLLED:
		del_timer_sync(&ghes->timer);
		break;
	case ACPI_HEST_NOTIFY_EXTERNAL:
		free_irq(ghes->irq, ghes);
		break;
	case ACPI_HEST_NOTIFY_SCI:
		mutex_lock(&ghes_list_mutex);
		list_del_rcu(&ghes->list);
		if (list_empty(&ghes_sci))
			unregister_acpi_hed_notifier(&ghes_notifier_sci);
		mutex_unlock(&ghes_list_mutex);
		break;
	case ACPI_HEST_NOTIFY_NMI:
		mutex_lock(&ghes_list_mutex);
		list_del_rcu(&ghes->list);
		if (list_empty(&ghes_nmi))
			unregister_die_notifier(&ghes_notifier_nmi);
		mutex_unlock(&ghes_list_mutex);
		/*
		 * To synchronize with NMI handler, ghes can only be
		 * freed after NMI handler finishes.
		 */
		synchronize_rcu();
		break;
	default:
		BUG();
		break;
	}

	ghes_fini(ghes);
	kfree(ghes);

	platform_set_drvdata(ghes_dev, NULL);

	return 0;
}

static struct platform_driver ghes_platform_driver = {
	.driver		= {
		.name	= "GHES",
		.owner	= THIS_MODULE,
	},
	.probe		= ghes_probe,
	.remove		= ghes_remove,
};

static int __init ghes_init(void)
{
	int rc;

	if (acpi_disabled)
		return -ENODEV;

	if (hest_disable) {
		pr_info(GHES_PFX "HEST is not enabled!\n");
		return -EINVAL;
	}

	rc = ghes_ioremap_init();
	if (rc)
		goto err;

	rc = platform_driver_register(&ghes_platform_driver);
	if (rc)
		goto err_ioremap_exit;

	return 0;
err_ioremap_exit:
	ghes_ioremap_exit();
err:
	return rc;
}

static void __exit ghes_exit(void)
{
	platform_driver_unregister(&ghes_platform_driver);
	ghes_ioremap_exit();
}

module_init(ghes_init);
module_exit(ghes_exit);

MODULE_AUTHOR("Huang Ying");
MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:GHES");