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 int lsb;
33
34 if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
35 return;
36
37 /*
38 * Even if the ->validation_bits are set for address mask,
39 * to be extra safe, check and reject an error radius '',
40 * and fall back to the default page size.
41 */
42 if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
43 lsb = find_first_bit((void *)&mem_err->physical_addr_mask, PAGE_SHIFT);
44 else
45 lsb = PAGE_SHIFT;
46
47 mce_setup(&m);
48 m.bank = -1;
49 /* Fake a memory read error with unknown channel */
50 m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | MCI_STATUS_MISCV | 0x9f;
51 m.misc = (MCI_MISC_ADDR_PHYS << 6) | lsb;
52
53 if (severity >= GHES_SEV_RECOVERABLE)
54 m.status |= MCI_STATUS_UC;
55
56 if (severity >= GHES_SEV_PANIC) {
57 m.status |= MCI_STATUS_PCC;
58 m.tsc = rdtsc();
59 }
60
61 m.addr = mem_err->physical_addr;
62 mce_log(&m);
63 }
64 EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
65
66 int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id)
67 {
68 const u64 *i_mce = ((const u64 *) (ctx_info + 1));
69 unsigned int cpu;
70 struct mce m;
71
72 if (!boot_cpu_has(X86_FEATURE_SMCA))
73 return -EINVAL;
74
75 /*
76 * The starting address of the register array extracted from BERT must
77 * match with the first expected register in the register layout of
78 * SMCA address space. This address corresponds to banks's MCA_STATUS
79 * register.
80 *
81 * Match any MCi_STATUS register by turning off bank numbers.
82 */
83 if ((ctx_info->msr_addr & MSR_AMD64_SMCA_MC0_STATUS) !=
84 MSR_AMD64_SMCA_MC0_STATUS)
85 return -EINVAL;
86
87 /*
88 * The register array size must be large enough to include all the
89 * SMCA registers which need to be extracted.
90 *
91 * The number of registers in the register array is determined by
92 * Register Array Size/8 as defined in UEFI spec v2.8, sec N.2.4.2.2.
93 * The register layout is fixed and currently the raw data in the
94 * register array includes 6 SMCA registers which the kernel can
95 * extract.
96 */
97 if (ctx_info->reg_arr_size < 48)
98 return -EINVAL;
99
100 mce_setup(&m);
101
102 m.extcpu = -1;
103 m.socketid = -1;
104
105 for_each_possible_cpu(cpu) {
106 if (cpu_data(cpu).topo.initial_apicid == lapic_id) {
107 m.extcpu = cpu;
108 m.socketid = cpu_data(m.extcpu).topo.pkg_id;
109 break;
110 }
111 }
112
113 m.apicid = lapic_id;
114 m.bank = (ctx_info->msr_addr >> 4) & 0xFF;
115 m.status = *i_mce;
116 m.addr = *(i_mce + 1);
117 m.misc = *(i_mce + 2);
118 /* Skipping MCA_CONFIG */
119 m.ipid = *(i_mce + 4);
120 m.synd = *(i_mce + 5);
121
122 mce_log(&m);
123
124 return 0;
125 }
126
127 #define CPER_CREATOR_MCE \
128 GUID_INIT(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c, \
129 0x64, 0x90, 0xb8, 0x9d)
130 #define CPER_SECTION_TYPE_MCE \
131 GUID_INIT(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96, \
132 0x04, 0x4a, 0x38, 0xfc)
133
134 /*
135 * CPER specification (in UEFI specification 2.3 appendix N) requires
136 * byte-packed.
137 */
138 struct cper_mce_record {
139 struct cper_record_header hdr;
140 struct cper_section_descriptor sec_hdr;
141 struct mce mce;
142 } __packed;
143
144 int apei_write_mce(struct mce *m)
145 {
146 struct cper_mce_record rcd;
147
148 memset(&rcd, 0, sizeof(rcd));
149 memcpy(rcd.hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
150 rcd.hdr.revision = CPER_RECORD_REV;
151 rcd.hdr.signature_end = CPER_SIG_END;
152 rcd.hdr.section_count = 1;
153 rcd.hdr.error_severity = CPER_SEV_FATAL;
154 /* timestamp, platform_id, partition_id are all invalid */
155 rcd.hdr.validation_bits = 0;
156 rcd.hdr.record_length = sizeof(rcd);
157 rcd.hdr.creator_id = CPER_CREATOR_MCE;
158 rcd.hdr.notification_type = CPER_NOTIFY_MCE;
159 rcd.hdr.record_id = cper_next_record_id();
160 rcd.hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
161
162 rcd.sec_hdr.section_offset = (void *)&rcd.mce - (void *)&rcd;
163 rcd.sec_hdr.section_length = sizeof(rcd.mce);
164 rcd.sec_hdr.revision = CPER_SEC_REV;
165 /* fru_id and fru_text is invalid */
166 rcd.sec_hdr.validation_bits = 0;
167 rcd.sec_hdr.flags = CPER_SEC_PRIMARY;
168 rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
169 rcd.sec_hdr.section_severity = CPER_SEV_FATAL;
170
171 memcpy(&rcd.mce, m, sizeof(*m));
172
173 return erst_write(&rcd.hdr);
174 }
175
176 ssize_t apei_read_mce(struct mce *m, u64 *record_id)
177 {
178 struct cper_mce_record rcd;
179 int rc, pos;
180
181 rc = erst_get_record_id_begin(&pos);
182 if (rc)
183 return rc;
184 retry:
185 rc = erst_get_record_id_next(&pos, record_id);
186 if (rc)
187 goto out;
188 /* no more record */
189 if (*record_id == APEI_ERST_INVALID_RECORD_ID)
190 goto out;
191 rc = erst_read_record(*record_id, &rcd.hdr, sizeof(rcd), sizeof(rcd),
192 &CPER_CREATOR_MCE);
193 /* someone else has cleared the record, try next one */
194 if (rc == -ENOENT)
195 goto retry;
196 else if (rc < 0)
197 goto out;
198
199 memcpy(m, &rcd.mce, sizeof(*m));
200 rc = sizeof(*m);
201 out:
202 erst_get_record_id_end();
203
204 return rc;
205 }
206
207 /* Check whether there is record in ERST */
208 int apei_check_mce(void)
209 {
210 return erst_get_record_count();
211 }
212
213 int apei_clear_mce(u64 record_id)
214 {
215 return erst_clear(record_id);
216 }
217
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.