LXR linux/arch/x86/kernel/cpu/mcheck/mce-apei.c

   1/*
   2 * Bridge between MCE and APEI
   3 *
   4 * On some machine, corrected memory errors are reported via APEI
   5 * generic hardware error source (GHES) instead of corrected Machine
   6 * Check. These corrected memory errors can be reported to user space
   7 * through /dev/mcelog via faking a corrected Machine Check, so that
   8 * the error memory page can be offlined by /sbin/mcelog if the error
   9 * count for one page is beyond the threshold.
  10 *
  11 * For fatal MCE, save MCE record into persistent storage via ERST, so
  12 * that the MCE record can be logged after reboot via ERST.
  13 *
  14 * Copyright 2010 Intel Corp.
  15 *   Author: Huang Ying <ying.huang@intel.com>
  16 *
  17 * This program is free software; you can redistribute it and/or
  18 * modify it under the terms of the GNU General Public License version
  19 * 2 as published by the Free Software Foundation.
  20 *
  21 * This program is distributed in the hope that it will be useful,
  22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 * GNU General Public License for more details.
  25 *
  26 * You should have received a copy of the GNU General Public License
  27 * along with this program; if not, write to the Free Software
  28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  29 */
  30
  31#include <linux/export.h>
  32#include <linux/kernel.h>
  33#include <linux/acpi.h>
  34#include <linux/cper.h>
  35#include <acpi/apei.h>
  36#include <acpi/ghes.h>
  37#include <asm/mce.h>
  38
  39#include "mce-internal.h"
  40
  41void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
  42{
  43        struct mce m;
  44
  45        if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
  46                return;
  47
  48        mce_setup(&m);
  49        m.bank = 1;
  50        /* Fake a memory read error with unknown channel */
  51        m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | 0x9f;
  52
  53        if (severity >= GHES_SEV_RECOVERABLE)
  54                m.status |= MCI_STATUS_UC;
  55        if (severity >= GHES_SEV_PANIC)
  56                m.status |= MCI_STATUS_PCC;
  57
  58        m.addr = mem_err->physical_addr;
  59        mce_log(&m);
  60}
  61EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
  62
  63#define CPER_CREATOR_MCE                                                \
  64        UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,     \
  65                0x64, 0x90, 0xb8, 0x9d)
  66#define CPER_SECTION_TYPE_MCE                                           \
  67        UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,     \
  68                0x04, 0x4a, 0x38, 0xfc)
  69
  70/*
  71 * CPER specification (in UEFI specification 2.3 appendix N) requires
  72 * byte-packed.
  73 */
  74struct cper_mce_record {
  75        struct cper_record_header hdr;
  76        struct cper_section_descriptor sec_hdr;
  77        struct mce mce;
  78} __packed;
  79
  80int apei_write_mce(struct mce *m)
  81{
  82        struct cper_mce_record rcd;
  83
  84        memset(&rcd, 0, sizeof(rcd));
  85        memcpy(rcd.hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
  86        rcd.hdr.revision = CPER_RECORD_REV;
  87        rcd.hdr.signature_end = CPER_SIG_END;
  88        rcd.hdr.section_count = 1;
  89        rcd.hdr.error_severity = CPER_SEV_FATAL;
  90        /* timestamp, platform_id, partition_id are all invalid */
  91        rcd.hdr.validation_bits = 0;
  92        rcd.hdr.record_length = sizeof(rcd);
  93        rcd.hdr.creator_id = CPER_CREATOR_MCE;
  94        rcd.hdr.notification_type = CPER_NOTIFY_MCE;
  95        rcd.hdr.record_id = cper_next_record_id();
  96        rcd.hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
  97
  98        rcd.sec_hdr.section_offset = (void *)&rcd.mce - (void *)&rcd;
  99        rcd.sec_hdr.section_length = sizeof(rcd.mce);
 100        rcd.sec_hdr.revision = CPER_SEC_REV;
 101        /* fru_id and fru_text is invalid */
 102        rcd.sec_hdr.validation_bits = 0;
 103        rcd.sec_hdr.flags = CPER_SEC_PRIMARY;
 104        rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
 105        rcd.sec_hdr.section_severity = CPER_SEV_FATAL;
 106
 107        memcpy(&rcd.mce, m, sizeof(*m));
 108
 109        return erst_write(&rcd.hdr);
 110}
 111
 112ssize_t apei_read_mce(struct mce *m, u64 *record_id)
 113{
 114        struct cper_mce_record rcd;
 115        int rc, pos;
 116
 117        rc = erst_get_record_id_begin(&pos);
 118        if (rc)
 119                return rc;
 120retry:
 121        rc = erst_get_record_id_next(&pos, record_id);
 122        if (rc)
 123                goto out;
 124        /* no more record */
 125        if (*record_id == APEI_ERST_INVALID_RECORD_ID)
 126                goto out;
 127        rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
 128        /* someone else has cleared the record, try next one */
 129        if (rc == -ENOENT)
 130                goto retry;
 131        else if (rc < 0)
 132                goto out;
 133        /* try to skip other type records in storage */
 134        else if (rc != sizeof(rcd) ||
 135                 uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE))
 136                goto retry;
 137        memcpy(m, &rcd.mce, sizeof(*m));
 138        rc = sizeof(*m);
 139out:
 140        erst_get_record_id_end();
 141
 142        return rc;
 143}
 144
 145/* Check whether there is record in ERST */
 146int apei_check_mce(void)
 147{
 148        return erst_get_record_count();
 149}
 150
 151int apei_clear_mce(u64 record_id)
 152{
 153        return erst_clear(record_id);
 154}
 155