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Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/mce-severity.c')
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-severity.c218
1 files changed, 218 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c
new file mode 100644
index 00000000000..ff0807f9705
--- /dev/null
+++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c
@@ -0,0 +1,218 @@
+/*
+ * MCE grading rules.
+ * Copyright 2008, 2009 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ *
+ * Author: Andi Kleen
+ */
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <asm/mce.h>
+
+#include "mce-internal.h"
+
+/*
+ * Grade an mce by severity. In general the most severe ones are processed
+ * first. Since there are quite a lot of combinations test the bits in a
+ * table-driven way. The rules are simply processed in order, first
+ * match wins.
+ *
+ * Note this is only used for machine check exceptions, the corrected
+ * errors use much simpler rules. The exceptions still check for the corrected
+ * errors, but only to leave them alone for the CMCI handler (except for
+ * panic situations)
+ */
+
+enum context { IN_KERNEL = 1, IN_USER = 2 };
+enum ser { SER_REQUIRED = 1, NO_SER = 2 };
+
+static struct severity {
+ u64 mask;
+ u64 result;
+ unsigned char sev;
+ unsigned char mcgmask;
+ unsigned char mcgres;
+ unsigned char ser;
+ unsigned char context;
+ unsigned char covered;
+ char *msg;
+} severities[] = {
+#define KERNEL .context = IN_KERNEL
+#define USER .context = IN_USER
+#define SER .ser = SER_REQUIRED
+#define NOSER .ser = NO_SER
+#define SEV(s) .sev = MCE_ ## s ## _SEVERITY
+#define BITCLR(x, s, m, r...) { .mask = x, .result = 0, SEV(s), .msg = m, ## r }
+#define BITSET(x, s, m, r...) { .mask = x, .result = x, SEV(s), .msg = m, ## r }
+#define MCGMASK(x, res, s, m, r...) \
+ { .mcgmask = x, .mcgres = res, SEV(s), .msg = m, ## r }
+#define MASK(x, y, s, m, r...) \
+ { .mask = x, .result = y, SEV(s), .msg = m, ## r }
+#define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
+#define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
+#define MCACOD 0xffff
+
+ BITCLR(MCI_STATUS_VAL, NO, "Invalid"),
+ BITCLR(MCI_STATUS_EN, NO, "Not enabled"),
+ BITSET(MCI_STATUS_PCC, PANIC, "Processor context corrupt"),
+ /* When MCIP is not set something is very confused */
+ MCGMASK(MCG_STATUS_MCIP, 0, PANIC, "MCIP not set in MCA handler"),
+ /* Neither return not error IP -- no chance to recover -> PANIC */
+ MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0, PANIC,
+ "Neither restart nor error IP"),
+ MCGMASK(MCG_STATUS_RIPV, 0, PANIC, "In kernel and no restart IP",
+ KERNEL),
+ BITCLR(MCI_STATUS_UC, KEEP, "Corrected error", NOSER),
+ MASK(MCI_STATUS_OVER|MCI_STATUS_UC|MCI_STATUS_EN, MCI_STATUS_UC, SOME,
+ "Spurious not enabled", SER),
+
+ /* ignore OVER for UCNA */
+ MASK(MCI_UC_SAR, MCI_STATUS_UC, KEEP,
+ "Uncorrected no action required", SER),
+ MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR, PANIC,
+ "Illegal combination (UCNA with AR=1)", SER),
+ MASK(MCI_STATUS_S, 0, KEEP, "Non signalled machine check", SER),
+
+ /* AR add known MCACODs here */
+ MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_SAR, PANIC,
+ "Action required with lost events", SER),
+ MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_SAR, PANIC,
+ "Action required; unknown MCACOD", SER),
+
+ /* known AO MCACODs: */
+ MASK(MCI_UC_SAR|MCI_STATUS_OVER|0xfff0, MCI_UC_S|0xc0, AO,
+ "Action optional: memory scrubbing error", SER),
+ MASK(MCI_UC_SAR|MCI_STATUS_OVER|MCACOD, MCI_UC_S|0x17a, AO,
+ "Action optional: last level cache writeback error", SER),
+
+ MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S, SOME,
+ "Action optional unknown MCACOD", SER),
+ MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S|MCI_STATUS_OVER, SOME,
+ "Action optional with lost events", SER),
+ BITSET(MCI_STATUS_UC|MCI_STATUS_OVER, PANIC, "Overflowed uncorrected"),
+ BITSET(MCI_STATUS_UC, UC, "Uncorrected"),
+ BITSET(0, SOME, "No match") /* always matches. keep at end */
+};
+
+/*
+ * If the EIPV bit is set, it means the saved IP is the
+ * instruction which caused the MCE.
+ */
+static int error_context(struct mce *m)
+{
+ if (m->mcgstatus & MCG_STATUS_EIPV)
+ return (m->ip && (m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
+ /* Unknown, assume kernel */
+ return IN_KERNEL;
+}
+
+int mce_severity(struct mce *a, int tolerant, char **msg)
+{
+ enum context ctx = error_context(a);
+ struct severity *s;
+
+ for (s = severities;; s++) {
+ if ((a->status & s->mask) != s->result)
+ continue;
+ if ((a->mcgstatus & s->mcgmask) != s->mcgres)
+ continue;
+ if (s->ser == SER_REQUIRED && !mce_ser)
+ continue;
+ if (s->ser == NO_SER && mce_ser)
+ continue;
+ if (s->context && ctx != s->context)
+ continue;
+ if (msg)
+ *msg = s->msg;
+ s->covered = 1;
+ if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
+ if (panic_on_oops || tolerant < 1)
+ return MCE_PANIC_SEVERITY;
+ }
+ return s->sev;
+ }
+}
+
+static void *s_start(struct seq_file *f, loff_t *pos)
+{
+ if (*pos >= ARRAY_SIZE(severities))
+ return NULL;
+ return &severities[*pos];
+}
+
+static void *s_next(struct seq_file *f, void *data, loff_t *pos)
+{
+ if (++(*pos) >= ARRAY_SIZE(severities))
+ return NULL;
+ return &severities[*pos];
+}
+
+static void s_stop(struct seq_file *f, void *data)
+{
+}
+
+static int s_show(struct seq_file *f, void *data)
+{
+ struct severity *ser = data;
+ seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
+ return 0;
+}
+
+static const struct seq_operations severities_seq_ops = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+static int severities_coverage_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &severities_seq_ops);
+}
+
+static ssize_t severities_coverage_write(struct file *file,
+ const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE(severities); i++)
+ severities[i].covered = 0;
+ return count;
+}
+
+static const struct file_operations severities_coverage_fops = {
+ .open = severities_coverage_open,
+ .release = seq_release,
+ .read = seq_read,
+ .write = severities_coverage_write,
+};
+
+static int __init severities_debugfs_init(void)
+{
+ struct dentry *dmce = NULL, *fseverities_coverage = NULL;
+
+ dmce = debugfs_create_dir("mce", NULL);
+ if (dmce == NULL)
+ goto err_out;
+ fseverities_coverage = debugfs_create_file("severities-coverage",
+ 0444, dmce, NULL,
+ &severities_coverage_fops);
+ if (fseverities_coverage == NULL)
+ goto err_out;
+
+ return 0;
+
+err_out:
+ if (fseverities_coverage)
+ debugfs_remove(fseverities_coverage);
+ if (dmce)
+ debugfs_remove(dmce);
+ return -ENOMEM;
+}
+late_initcall(severities_debugfs_init);