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 } 146