/*

 * Bridge between MCE and APEI

 *

 * On some machine, corrected memory errors are reported via APEI

 * generic hardware error source (GHES) instead of corrected Machine

 * Check. These corrected memory errors can be reported to user space

 * through /dev/mcelog via faking a corrected Machine Check, so that

 * the error memory page can be offlined by /sbin/mcelog if the error

 * count for one page is beyond the threshold.

 *

 * For fatal MCE, save MCE record into persistent storage via ERST, so

 * that the MCE record can be logged after reboot via ERST.

 *

 * Copyright 2010 Intel Corp.

 *   Author: Huang Ying <ying.huang@intel.com>

 *   Ported by: Liu, Jinsong <jinsong.liu@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, see <http://www.gnu.org/licenses/>.

 */

#include <xen/kernel.h>

#include <xen/cper.h>

#include <xen/errno.h>

#include <acpi/acpi.h>

#include <acpi/apei.h>

#include "mce.h"

#define CPER_CREATOR_MCE            \

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

    0x64, 0x90, 0xb8, 0x9d)

#define CPER_SECTION_TYPE_MCE           \

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

    0x04, 0x4a, 0x38, 0xfc)

/*

 * CPER specification (in UEFI specification 2.3 appendix N) requires

 * byte-packed.

 */

struct __packed cper_mce_record {

  struct cper_record_header hdr;

  struct cper_section_descriptor sec_hdr;

  struct mce mce;

};

int apei_write_mce(struct mce *m)

{

  struct cper_mce_record rcd;

  if (!m)

    return -EINVAL;

  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_SER_FATAL;

  /* timestamp, platform_id, partition_id are all invalid */

  rcd.hdr.validation_bits = 0;

  rcd.hdr.record_length = sizeof(rcd);

  rcd.hdr.creator_id = CPER_CREATOR_MCE;

  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 = (void *)&rcd.mce - (void *)&rcd;

  rcd.sec_hdr.section_length = sizeof(rcd.mce);

  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;

  rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;

  rcd.sec_hdr.section_severity = CPER_SER_FATAL;

  memcpy(&rcd.mce, m, sizeof(*m));

  return erst_write(&rcd.hdr);

}

#ifndef NDEBUG /* currently dead code */

ssize_t apei_read_mce(struct mce *m, u64 *record_id)

{

  struct cper_mce_record rcd;

  ssize_t len;

  if (!m || !record_id)

    return -EINVAL;

  len = erst_read_next(&rcd.hdr, sizeof(rcd));

  if (len <= 0)

    return len;

  /* Can not skip other records in storage via ERST unless clear them */

  else if (len != sizeof(rcd) ||

     uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE)) {

    printk(KERN_WARNING

      "MCE-APEI: Can not skip the unknown record in ERST");

    return -EIO;

  }

  memcpy(m, &rcd.mce, sizeof(*m));

  *record_id = rcd.hdr.record_id;

  return sizeof(*m);

}

/* Check whether there is record in ERST */

bool apei_check_mce(void)

{

  return erst_get_record_count() > 0;

}

int apei_clear_mce(u64 record_id)

{

  return erst_clear(record_id);

}

#endif /* currently dead code */