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 MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c }
47 #define KERNEL .context = IN_KERNEL
48 #define USER .context = IN_USER
49 #define SER .ser = SER_REQUIRED
50 #define NOSER .ser = NO_SER
51 #define BITCLR(x) .mask = x, .result = 0
52 #define BITSET(x) .mask = x, .result = x
53 #define MCGMASK(x, y) .mcgmask = x, .mcgres = y
54 #define MASK(x, y) .mask = x, .result = y
55 #define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
56 #define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
61 BITCLR(MCI_STATUS_VAL)
68 PANIC, "Processor context corrupt",
69 BITSET(MCI_STATUS_PCC)
71 /* When MCIP is not set something is very confused */
73 PANIC, "MCIP not set in MCA handler",
74 MCGMASK(MCG_STATUS_MCIP, 0)
76 /* Neither return not error IP -- no chance to recover -> PANIC */
78 PANIC, "Neither restart nor error IP",
79 MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
82 PANIC, "In kernel and no restart IP",
83 KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
86 KEEP, "Corrected error",
87 NOSER, BITCLR(MCI_STATUS_UC)
90 /* ignore OVER for UCNA */
92 KEEP, "Uncorrected no action required",
93 SER, MASK(MCI_UC_SAR, MCI_STATUS_UC)
96 PANIC, "Illegal combination (UCNA with AR=1)",
98 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR)
101 KEEP, "Non signalled machine check",
102 SER, MASK(MCI_STATUS_S, 0)
105 /* AR add known MCACODs here */
107 PANIC, "Action required with lost events",
109 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_SAR)
112 PANIC, "Action required; unknown MCACOD",
113 SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_SAR)
116 /* known AO MCACODs: */
118 AO, "Action optional: memory scrubbing error",
119 SER, MASK(MCI_UC_SAR|MCI_STATUS_OVER|0xfff0, MCI_UC_S|0xc0)
122 AO, "Action optional: last level cache writeback error",
123 SER, MASK(MCI_UC_SAR|MCI_STATUS_OVER|MCACOD, MCI_UC_S|0x17a)
126 SOME, "Action optional unknown MCACOD",
127 SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S)
130 SOME, "Action optional with lost events",
131 SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S|MCI_STATUS_OVER)
135 PANIC, "Overflowed uncorrected",
136 BITSET(MCI_STATUS_UC|MCI_STATUS_OVER)
140 BITSET(MCI_STATUS_UC)
145 ) /* always matches. keep at end */
149 * If the EIPV bit is set, it means the saved IP is the
150 * instruction which caused the MCE.
152 static int error_context(struct mce *m)
154 if (m->mcgstatus & MCG_STATUS_EIPV)
155 return (m->ip && (m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
156 /* Unknown, assume kernel */
160 int mce_severity(struct mce *a, int tolerant, char **msg)
162 enum context ctx = error_context(a);
165 for (s = severities;; s++) {
166 if ((a->status & s->mask) != s->result)
168 if ((a->mcgstatus & s->mcgmask) != s->mcgres)
170 if (s->ser == SER_REQUIRED && !mce_ser)
172 if (s->ser == NO_SER && mce_ser)
174 if (s->context && ctx != s->context)
179 if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
180 if (panic_on_oops || tolerant < 1)
181 return MCE_PANIC_SEVERITY;
187 #ifdef CONFIG_DEBUG_FS
188 static void *s_start(struct seq_file *f, loff_t *pos)
190 if (*pos >= ARRAY_SIZE(severities))
192 return &severities[*pos];
195 static void *s_next(struct seq_file *f, void *data, loff_t *pos)
197 if (++(*pos) >= ARRAY_SIZE(severities))
199 return &severities[*pos];
202 static void s_stop(struct seq_file *f, void *data)
206 static int s_show(struct seq_file *f, void *data)
208 struct severity *ser = data;
209 seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
213 static const struct seq_operations severities_seq_ops = {
220 static int severities_coverage_open(struct inode *inode, struct file *file)
222 return seq_open(file, &severities_seq_ops);
225 static ssize_t severities_coverage_write(struct file *file,
226 const char __user *ubuf,
227 size_t count, loff_t *ppos)
230 for (i = 0; i < ARRAY_SIZE(severities); i++)
231 severities[i].covered = 0;
235 static const struct file_operations severities_coverage_fops = {
236 .open = severities_coverage_open,
237 .release = seq_release,
239 .write = severities_coverage_write,
243 static int __init severities_debugfs_init(void)
245 struct dentry *dmce = NULL, *fseverities_coverage = NULL;
247 dmce = mce_get_debugfs_dir();
250 fseverities_coverage = debugfs_create_file("severities-coverage",
252 &severities_coverage_fops);
253 if (fseverities_coverage == NULL)
261 late_initcall(severities_debugfs_init);