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Commit 0bb77c46 authored by Tony Luck's avatar Tony Luck
Browse files

pstore: X86 platform interface using ACPI/APEI/ERST 



The 'error record serialization table' in ACPI provides a suitable
amount of persistent storage for use by the pstore filesystem.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent ca01d6dd

drivers/acpi/apei/Kconfig

+1 −0
Original line number Diff line number Diff line 
config ACPI_APEI

	bool "ACPI Platform Error Interface (APEI)"

	select PSTORE

	depends on X86

	help

	  APEI allows to report errors (for example from the chipset)

drivers/acpi/apei/erst.c

+136 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/cper.h>

#include <linux/nmi.h>

#include <linux/hardirq.h>

#include <linux/pstore.h>

#include <acpi/apei.h>



#include "apei-internal.h"
@@ -781,6 +782,128 @@ static int erst_check_table(struct acpi_table_erst *erst_tab) 
	return 0;

}



static size_t erst_reader(u64 *id, enum pstore_type_id *type,

		       struct timespec *time);

static u64 erst_writer(enum pstore_type_id type, size_t size);



static struct pstore_info erst_info = {

	.owner		= THIS_MODULE,

	.name		= "erst",

	.read		= erst_reader,

	.write		= erst_writer,

	.erase		= erst_clear

};



#define CPER_CREATOR_PSTORE						\

	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\

		0x64, 0x90, 0xb8, 0x9d)

#define CPER_SECTION_TYPE_DMESG						\

	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\

		0x94, 0x19, 0xeb, 0x12)

#define CPER_SECTION_TYPE_MCE						\

	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\

		0x04, 0x4a, 0x38, 0xfc)



struct cper_pstore_record {

	struct cper_record_header hdr;

	struct cper_section_descriptor sec_hdr;

	char data[];

} __packed;



static size_t erst_reader(u64 *id, enum pstore_type_id *type,

		       struct timespec *time)

{

	int rc;

	ssize_t len;

	unsigned long flags;

	u64 record_id;

	struct cper_pstore_record *rcd = (struct cper_pstore_record *)

					(erst_info.buf - sizeof(*rcd));



	if (erst_disable)

		return -ENODEV;



	raw_spin_lock_irqsave(&erst_lock, flags);

skip:

	rc = __erst_get_next_record_id(&record_id);

	if (rc) {

		raw_spin_unlock_irqrestore(&erst_lock, flags);

		return rc;

	}

	/* no more record */

	if (record_id == APEI_ERST_INVALID_RECORD_ID) {

		raw_spin_unlock_irqrestore(&erst_lock, flags);

		return 0;

	}



	len = __erst_read(record_id, &rcd->hdr, sizeof(*rcd) +

			  erst_erange.size);

	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)

		goto skip;

	raw_spin_unlock_irqrestore(&erst_lock, flags);



	*id = record_id;

	if (uuid_le_cmp(rcd->sec_hdr.section_type,

			CPER_SECTION_TYPE_DMESG) == 0)

		*type = PSTORE_TYPE_DMESG;

	else if (uuid_le_cmp(rcd->sec_hdr.section_type,

			     CPER_SECTION_TYPE_MCE) == 0)

		*type = PSTORE_TYPE_MCE;

	else

		*type = PSTORE_TYPE_UNKNOWN;



	if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)

		time->tv_sec = rcd->hdr.timestamp;

	else

		time->tv_sec = 0;

	time->tv_nsec = 0;



	return len - sizeof(*rcd);

}



static u64 erst_writer(enum pstore_type_id type, size_t size)

{

	struct cper_pstore_record *rcd = (struct cper_pstore_record *)

					(erst_info.buf - sizeof(*rcd));



	memset(rcd, 0, sizeof(*rcd));

	memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);

	rcd->hdr.revision = CPER_RECORD_REV;

	rcd->hdr.signature_end = CPER_SIG_END;

	rcd->hdr.section_count = 1;

	rcd->hdr.error_severity = CPER_SEV_FATAL;

	/* timestamp valid. platform_id, partition_id are invalid */

	rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;

	rcd->hdr.timestamp = get_seconds();

	rcd->hdr.record_length = sizeof(*rcd) + size;

	rcd->hdr.creator_id = CPER_CREATOR_PSTORE;

	rcd->hdr.notification_type = CPER_NOTIFY_MCE;

	rcd->hdr.record_id = cper_next_record_id();

	rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;



	rcd->sec_hdr.section_offset = sizeof(*rcd);

	rcd->sec_hdr.section_length = size;

	rcd->sec_hdr.revision = CPER_SEC_REV;

	/* fru_id and fru_text is invalid */

	rcd->sec_hdr.validation_bits = 0;

	rcd->sec_hdr.flags = CPER_SEC_PRIMARY;

	switch (type) {

	case PSTORE_TYPE_DMESG:

		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;

		break;

	case PSTORE_TYPE_MCE:

		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;

		break;

	default:

		return -EINVAL;

	}

	rcd->sec_hdr.section_severity = CPER_SEV_FATAL;



	erst_write(&rcd->hdr);



	return rcd->hdr.record_id;

}



static int __init erst_init(void)

{

	int rc = 0;
@@ -788,6 +911,7 @@ static int __init erst_init(void) 
	struct apei_exec_context ctx;

	struct apei_resources erst_resources;

	struct resource *r;

	char *buf;



	if (acpi_disabled)

		goto err;
@@ -854,6 +978,18 @@ static int __init erst_init(void) 
	if (!erst_erange.vaddr)

		goto err_release_erange;



	buf = kmalloc(erst_erange.size, GFP_KERNEL);

	mutex_init(&erst_info.buf_mutex);

	if (buf) {

		erst_info.buf = buf + sizeof(struct cper_pstore_record);

		erst_info.bufsize = erst_erange.size -

				    sizeof(struct cper_pstore_record);

		if (pstore_register(&erst_info)) {

			pr_info(ERST_PFX "Could not register with persistent store\n");

			kfree(buf);

		}

	}



	pr_info(ERST_PFX

	"Error Record Serialization Table (ERST) support is initialized.\n");