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 39void 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} 55EXPORT_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 */ 68struct cper_mce_record { 69 struct cper_record_header hdr; 70 struct cper_section_descriptor sec_hdr; 71 struct mce mce; 72} __packed; 73 74int 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 106ssize_t apei_read_mce(struct mce *m, u64 *record_id) 107{ 108 struct cper_mce_record rcd; 109 ssize_t len; 110 111 len = erst_read_next(&rcd.hdr, sizeof(rcd)); 112 if (len <= 0) 113 return len; 114 /* Can not skip other records in storage via ERST unless clear them */ 115 else if (len != sizeof(rcd) || 116 uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE)) { 117 if (printk_ratelimit()) 118 pr_warning( 119 "MCE-APEI: Can not skip the unknown record in ERST"); 120 return -EIO; 121 } 122 123 memcpy(m, &rcd.mce, sizeof(*m)); 124 *record_id = rcd.hdr.record_id; 125 126 return sizeof(*m); 127} 128 129/* Check whether there is record in ERST */ 130int apei_check_mce(void) 131{ 132 return erst_get_record_count(); 133} 134 135int apei_clear_mce(u64 record_id) 136{ 137 return erst_clear(record_id); 138} 139