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/kernel.h>
  32 #include <linux/acpi.h>
  33 #include <linux/cper.h>
  34 #include <acpi/apei.h>
  35 #include <asm/mce.h>
  36
  37 #include "mce-internal.h"
  38
  39 void apei_mce_report_mem_error(int corrected, struct cper_sec_mem_err *mem_err)
  40 {
  41         struct mce m;
  42
  43         /* Only corrected MC is reported */
  44         if (!corrected)
  45                 return;
  46
  47         mce_setup(&m);
  48         m.bank = 1;
  49         /* Fake a memory read corrected error with unknown channel */
  50         m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | 0x9f;
  51         m.addr = mem_err->physical_addr;
  52         mce_log(&m);
  53         mce_notify_irq();
  54 }
  55 EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
  56
  57 #define CPER_CREATOR_MCE                                                \
  58         UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,     \
  59                 0x64, 0x90, 0xb8, 0x9d)
  60 #define CPER_SECTION_TYPE_MCE                                           \
  61         UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,     \
  62                 0x04, 0x4a, 0x38, 0xfc)
  63
  64 /*
  65  * CPER specification (in UEFI specification 2.3 appendix N) requires
  66  * byte-packed.
  67  */
  68 struct cper_mce_record {
  69         struct cper_record_header hdr;
  70         struct cper_section_descriptor sec_hdr;
  71         struct mce mce;
  72 } __packed;
  73
  74 int apei_write_mce(struct mce *m)
  75 {
  76         struct cper_mce_record rcd;
  77
  78         memset(&rcd, 0, sizeof(rcd));
  79         memcpy(rcd.hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
  80         rcd.hdr.revision = CPER_RECORD_REV;
  81         rcd.hdr.signature_end = CPER_SIG_END;
  82         rcd.hdr.section_count = 1;
  83         rcd.hdr.error_severity = CPER_SEV_FATAL;
  84         /* timestamp, platform_id, partition_id are all invalid */
  85         rcd.hdr.validation_bits = 0;
  86         rcd.hdr.record_length = sizeof(rcd);
  87         rcd.hdr.creator_id = CPER_CREATOR_MCE;
  88         rcd.hdr.notification_type = CPER_NOTIFY_MCE;
  89         rcd.hdr.record_id = cper_next_record_id();
  90         rcd.hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
  91
  92         rcd.sec_hdr.section_offset = (void *)&rcd.mce - (void *)&rcd;
  93         rcd.sec_hdr.section_length = sizeof(rcd.mce);
  94         rcd.sec_hdr.revision = CPER_SEC_REV;
  95         /* fru_id and fru_text is invalid */
  96         rcd.sec_hdr.validation_bits = 0;
  97         rcd.sec_hdr.flags = CPER_SEC_PRIMARY;
  98         rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
  99         rcd.sec_hdr.section_severity = CPER_SEV_FATAL;
 100
 101         memcpy(&rcd.mce, m, sizeof(*m));
 102
 103         return erst_write(&rcd.hdr);
 104 }
 105
 106 ssize_t apei_read_mce(struct mce *m, u64 *record_id)
 107 {
 108         struct cper_mce_record rcd;
 109         int rc, pos;
 110
 111         rc = erst_get_record_id_begin(&pos);
 112         if (rc)
 113                 return rc;
 114 retry:
 115         rc = erst_get_record_id_next(&pos, record_id);
 116         if (rc)
 117                 goto out;
 118         /* no more record */
 119         if (*record_id == APEI_ERST_INVALID_RECORD_ID)
 120                 goto out;
 121         rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
 122         /* someone else has cleared the record, try next one */
 123         if (rc == -ENOENT)
 124                 goto retry;
 125         else if (rc < 0)
 126                 goto out;
 127         /* try to skip other type records in storage */
 128         else if (rc != sizeof(rcd) ||
 129                  uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE))
 130                 goto retry;
 131         memcpy(m, &rcd.mce, sizeof(*m));
 132         rc = sizeof(*m);
 133 out:
 134         erst_get_record_id_end();
 135
 136         return rc;
 137 }
 138
 139 /* Check whether there is record in ERST */
 140 int apei_check_mce(void)
 141 {
 142         return erst_get_record_count();
 143 }
 144
 145 int apei_clear_mce(u64 record_id)
 146 {
 147         return erst_clear(record_id);
 148 }