root/arch/x86/kernel/cpu/mce/apei.c

DEFINITIONS

1. apei_mce_report_mem_error
2. apei_write_mce
3. apei_read_mce
4. apei_check_mce
5. apei_clear_mce

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Bridge between MCE and APEI
   4  *
   5  * On some machine, corrected memory errors are reported via APEI
   6  * generic hardware error source (GHES) instead of corrected Machine
   7  * Check. These corrected memory errors can be reported to user space
   8  * through /dev/mcelog via faking a corrected Machine Check, so that
   9  * the error memory page can be offlined by /sbin/mcelog if the error
  10  * count for one page is beyond the threshold.
  11  *
  12  * For fatal MCE, save MCE record into persistent storage via ERST, so
  13  * that the MCE record can be logged after reboot via ERST.
  14  *
  15  * Copyright 2010 Intel Corp.
  16  *   Author: Huang Ying <ying.huang@intel.com>
  17  */
  18 
  19 #include <linux/export.h>
  20 #include <linux/kernel.h>
  21 #include <linux/acpi.h>
  22 #include <linux/cper.h>
  23 #include <acpi/apei.h>
  24 #include <acpi/ghes.h>
  25 #include <asm/mce.h>
  26 
  27 #include "internal.h"
  28 
  29 void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
  30 {
  31         struct mce m;
  32 
  33         if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
  34                 return;
  35 
  36         mce_setup(&m);
  37         m.bank = -1;
  38         /* Fake a memory read error with unknown channel */
  39         m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | 0x9f;
  40 
  41         if (severity >= GHES_SEV_RECOVERABLE)
  42                 m.status |= MCI_STATUS_UC;
  43 
  44         if (severity >= GHES_SEV_PANIC) {
  45                 m.status |= MCI_STATUS_PCC;
  46                 m.tsc = rdtsc();
  47         }
  48 
  49         m.addr = mem_err->physical_addr;
  50         mce_log(&m);
  51 }
  52 EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
  53 
  54 #define CPER_CREATOR_MCE                                                \
  55         GUID_INIT(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,   \
  56                   0x64, 0x90, 0xb8, 0x9d)
  57 #define CPER_SECTION_TYPE_MCE                                           \
  58         GUID_INIT(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,   \
  59                   0x04, 0x4a, 0x38, 0xfc)
  60 
  61 /*
  62  * CPER specification (in UEFI specification 2.3 appendix N) requires
  63  * byte-packed.
  64  */
  65 struct cper_mce_record {
  66         struct cper_record_header hdr;
  67         struct cper_section_descriptor sec_hdr;
  68         struct mce mce;
  69 } __packed;
  70 
  71 int apei_write_mce(struct mce *m)
  72 {
  73         struct cper_mce_record rcd;
  74 
  75         memset(&rcd, 0, sizeof(rcd));
  76         memcpy(rcd.hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
  77         rcd.hdr.revision = CPER_RECORD_REV;
  78         rcd.hdr.signature_end = CPER_SIG_END;
  79         rcd.hdr.section_count = 1;
  80         rcd.hdr.error_severity = CPER_SEV_FATAL;
  81         /* timestamp, platform_id, partition_id are all invalid */
  82         rcd.hdr.validation_bits = 0;
  83         rcd.hdr.record_length = sizeof(rcd);
  84         rcd.hdr.creator_id = CPER_CREATOR_MCE;
  85         rcd.hdr.notification_type = CPER_NOTIFY_MCE;
  86         rcd.hdr.record_id = cper_next_record_id();
  87         rcd.hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
  88 
  89         rcd.sec_hdr.section_offset = (void *)&rcd.mce - (void *)&rcd;
  90         rcd.sec_hdr.section_length = sizeof(rcd.mce);
  91         rcd.sec_hdr.revision = CPER_SEC_REV;
  92         /* fru_id and fru_text is invalid */
  93         rcd.sec_hdr.validation_bits = 0;
  94         rcd.sec_hdr.flags = CPER_SEC_PRIMARY;
  95         rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
  96         rcd.sec_hdr.section_severity = CPER_SEV_FATAL;
  97 
  98         memcpy(&rcd.mce, m, sizeof(*m));
  99 
 100         return erst_write(&rcd.hdr);
 101 }
 102 
 103 ssize_t apei_read_mce(struct mce *m, u64 *record_id)
 104 {
 105         struct cper_mce_record rcd;
 106         int rc, pos;
 107 
 108         rc = erst_get_record_id_begin(&pos);
 109         if (rc)
 110                 return rc;
 111 retry:
 112         rc = erst_get_record_id_next(&pos, record_id);
 113         if (rc)
 114                 goto out;
 115         /* no more record */
 116         if (*record_id == APEI_ERST_INVALID_RECORD_ID)
 117                 goto out;
 118         rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
 119         /* someone else has cleared the record, try next one */
 120         if (rc == -ENOENT)
 121                 goto retry;
 122         else if (rc < 0)
 123                 goto out;
 124         /* try to skip other type records in storage */
 125         else if (rc != sizeof(rcd) ||
 126                  !guid_equal(&rcd.hdr.creator_id, &CPER_CREATOR_MCE))
 127                 goto retry;
 128         memcpy(m, &rcd.mce, sizeof(*m));
 129         rc = sizeof(*m);
 130 out:
 131         erst_get_record_id_end();
 132 
 133         return rc;
 134 }
 135 
 136 /* Check whether there is record in ERST */
 137 int apei_check_mce(void)
 138 {
 139         return erst_get_record_count();
 140 }
 141 
 142 int apei_clear_mce(u64 record_id)
 143 {
 144         return erst_clear(record_id);
 145 }