3 * Copyright 2008, 2009 Intel Corporation.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; version 2
12 #include <linux/kernel.h>
13 #include <linux/seq_file.h>
14 #include <linux/init.h>
15 #include <linux/debugfs.h>
18 #include "mce-internal.h"
21 * Grade an mce by severity. In general the most severe ones are processed
22 * first. Since there are quite a lot of combinations test the bits in a
23 * table-driven way. The rules are simply processed in order, first
26 * Note this is only used for machine check exceptions, the corrected
27 * errors use much simpler rules. The exceptions still check for the corrected
28 * errors, but only to leave them alone for the CMCI handler (except for
32 enum context { IN_KERNEL = 1, IN_USER = 2 };
33 enum ser { SER_REQUIRED = 1, NO_SER = 2 };
35 static struct severity {
39 unsigned char mcgmask;
42 unsigned char context;
43 unsigned char covered;
46 #define KERNEL .context = IN_KERNEL
47 #define USER .context = IN_USER
48 #define SER .ser = SER_REQUIRED
49 #define NOSER .ser = NO_SER
50 #define SEV(s) .sev = MCE_ ## s ## _SEVERITY
51 #define BITCLR(x, s, m, r...) { .mask = x, .result = 0, SEV(s), .msg = m, ## r }
52 #define BITSET(x, s, m, r...) { .mask = x, .result = x, SEV(s), .msg = m, ## r }
53 #define MCGMASK(x, res, s, m, r...) \
54 { .mcgmask = x, .mcgres = res, SEV(s), .msg = m, ## r }
55 #define MASK(x, y, s, m, r...) \
56 { .mask = x, .result = y, SEV(s), .msg = m, ## r }
57 #define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
58 #define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
71 PANIC, "Processor context corrupt"
73 /* When MCIP is not set something is very confused */
76 PANIC, "MCIP not set in MCA handler"
78 /* Neither return not error IP -- no chance to recover -> PANIC */
80 MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0,
81 PANIC, "Neither restart nor error IP"
85 PANIC, "In kernel and no restart IP",
90 KEEP, "Corrected error",
94 /* ignore OVER for UCNA */
96 MCI_UC_SAR, MCI_STATUS_UC,
97 KEEP, "Uncorrected no action required",
101 MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR,
102 PANIC, "Illegal combination (UCNA with AR=1)",
107 KEEP, "Non signalled machine check",
111 /* AR add known MCACODs here */
113 MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_SAR,
114 PANIC, "Action required with lost events",
118 MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_SAR,
119 PANIC, "Action required; unknown MCACOD",
123 /* known AO MCACODs: */
125 MCI_UC_SAR|MCI_STATUS_OVER|0xfff0, MCI_UC_S|0xc0,
126 AO, "Action optional: memory scrubbing error",
130 MCI_UC_SAR|MCI_STATUS_OVER|MCACOD, MCI_UC_S|0x17a,
131 AO, "Action optional: last level cache writeback error",
136 MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S,
137 SOME, "Action optional unknown MCACOD",
141 MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S|MCI_STATUS_OVER,
142 SOME, "Action optional with lost events",
146 MCI_STATUS_UC|MCI_STATUS_OVER,
147 PANIC, "Overflowed uncorrected"
156 ) /* always matches. keep at end */
160 * If the EIPV bit is set, it means the saved IP is the
161 * instruction which caused the MCE.
163 static int error_context(struct mce *m)
165 if (m->mcgstatus & MCG_STATUS_EIPV)
166 return (m->ip && (m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
167 /* Unknown, assume kernel */
171 int mce_severity(struct mce *a, int tolerant, char **msg)
173 enum context ctx = error_context(a);
176 for (s = severities;; s++) {
177 if ((a->status & s->mask) != s->result)
179 if ((a->mcgstatus & s->mcgmask) != s->mcgres)
181 if (s->ser == SER_REQUIRED && !mce_ser)
183 if (s->ser == NO_SER && mce_ser)
185 if (s->context && ctx != s->context)
190 if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
191 if (panic_on_oops || tolerant < 1)
192 return MCE_PANIC_SEVERITY;
198 #ifdef CONFIG_DEBUG_FS
199 static void *s_start(struct seq_file *f, loff_t *pos)
201 if (*pos >= ARRAY_SIZE(severities))
203 return &severities[*pos];
206 static void *s_next(struct seq_file *f, void *data, loff_t *pos)
208 if (++(*pos) >= ARRAY_SIZE(severities))
210 return &severities[*pos];
213 static void s_stop(struct seq_file *f, void *data)
217 static int s_show(struct seq_file *f, void *data)
219 struct severity *ser = data;
220 seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
224 static const struct seq_operations severities_seq_ops = {
231 static int severities_coverage_open(struct inode *inode, struct file *file)
233 return seq_open(file, &severities_seq_ops);
236 static ssize_t severities_coverage_write(struct file *file,
237 const char __user *ubuf,
238 size_t count, loff_t *ppos)
241 for (i = 0; i < ARRAY_SIZE(severities); i++)
242 severities[i].covered = 0;
246 static const struct file_operations severities_coverage_fops = {
247 .open = severities_coverage_open,
248 .release = seq_release,
250 .write = severities_coverage_write,
254 static int __init severities_debugfs_init(void)
256 struct dentry *dmce = NULL, *fseverities_coverage = NULL;
258 dmce = mce_get_debugfs_dir();
261 fseverities_coverage = debugfs_create_file("severities-coverage",
263 &severities_coverage_fops);
264 if (fseverities_coverage == NULL)
272 late_initcall(severities_debugfs_init);