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12#include <linux/kernel.h>
13#include <linux/seq_file.h>
14#include <linux/init.h>
15#include <linux/debugfs.h>
16#include <asm/mce.h>
17
18#include "mce-internal.h"
19
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31
32enum context { IN_KERNEL = 1, IN_USER = 2 };
33enum ser { SER_REQUIRED = 1, NO_SER = 2 };
34
35static struct severity {
36 u64 mask;
37 u64 result;
38 unsigned char sev;
39 unsigned char mcgmask;
40 unsigned char mcgres;
41 unsigned char ser;
42 unsigned char context;
43 unsigned char covered;
44 char *msg;
45} severities[] = {
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)
59#define MCACOD 0xffff
60
61 BITCLR(MCI_STATUS_VAL, NO, "Invalid"),
62 BITCLR(MCI_STATUS_EN, NO, "Not enabled"),
63 BITSET(MCI_STATUS_PCC, PANIC, "Processor context corrupt"),
64
65 MCGMASK(MCG_STATUS_MCIP, 0, PANIC, "MCIP not set in MCA handler"),
66
67 MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0, PANIC,
68 "Neither restart nor error IP"),
69 MCGMASK(MCG_STATUS_RIPV, 0, PANIC, "In kernel and no restart IP",
70 KERNEL),
71 BITCLR(MCI_STATUS_UC, KEEP, "Corrected error", NOSER),
72 MASK(MCI_STATUS_OVER|MCI_STATUS_UC|MCI_STATUS_EN, MCI_STATUS_UC, SOME,
73 "Spurious not enabled", SER),
74
75
76 MASK(MCI_UC_SAR, MCI_STATUS_UC, KEEP,
77 "Uncorrected no action required", SER),
78 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR, PANIC,
79 "Illegal combination (UCNA with AR=1)", SER),
80 MASK(MCI_STATUS_S, 0, KEEP, "Non signalled machine check", SER),
81
82
83 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_SAR, PANIC,
84 "Action required with lost events", SER),
85 MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_SAR, PANIC,
86 "Action required; unknown MCACOD", SER),
87
88
89 MASK(MCI_UC_SAR|MCI_STATUS_OVER|0xfff0, MCI_UC_S|0xc0, AO,
90 "Action optional: memory scrubbing error", SER),
91 MASK(MCI_UC_SAR|MCI_STATUS_OVER|MCACOD, MCI_UC_S|0x17a, AO,
92 "Action optional: last level cache writeback error", SER),
93
94 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S, SOME,
95 "Action optional unknown MCACOD", SER),
96 MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S|MCI_STATUS_OVER, SOME,
97 "Action optional with lost events", SER),
98 BITSET(MCI_STATUS_UC|MCI_STATUS_OVER, PANIC, "Overflowed uncorrected"),
99 BITSET(MCI_STATUS_UC, UC, "Uncorrected"),
100 BITSET(0, SOME, "No match")
101};
102
103
104
105
106
107static int error_context(struct mce *m)
108{
109 if (m->mcgstatus & MCG_STATUS_EIPV)
110 return (m->ip && (m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
111
112 return IN_KERNEL;
113}
114
115int mce_severity(struct mce *a, int tolerant, char **msg)
116{
117 enum context ctx = error_context(a);
118 struct severity *s;
119
120 for (s = severities;; s++) {
121 if ((a->status & s->mask) != s->result)
122 continue;
123 if ((a->mcgstatus & s->mcgmask) != s->mcgres)
124 continue;
125 if (s->ser == SER_REQUIRED && !mce_ser)
126 continue;
127 if (s->ser == NO_SER && mce_ser)
128 continue;
129 if (s->context && ctx != s->context)
130 continue;
131 if (msg)
132 *msg = s->msg;
133 s->covered = 1;
134 if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
135 if (panic_on_oops || tolerant < 1)
136 return MCE_PANIC_SEVERITY;
137 }
138 return s->sev;
139 }
140}
141
142#ifdef CONFIG_DEBUG_FS
143static void *s_start(struct seq_file *f, loff_t *pos)
144{
145 if (*pos >= ARRAY_SIZE(severities))
146 return NULL;
147 return &severities[*pos];
148}
149
150static void *s_next(struct seq_file *f, void *data, loff_t *pos)
151{
152 if (++(*pos) >= ARRAY_SIZE(severities))
153 return NULL;
154 return &severities[*pos];
155}
156
157static void s_stop(struct seq_file *f, void *data)
158{
159}
160
161static int s_show(struct seq_file *f, void *data)
162{
163 struct severity *ser = data;
164 seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
165 return 0;
166}
167
168static const struct seq_operations severities_seq_ops = {
169 .start = s_start,
170 .next = s_next,
171 .stop = s_stop,
172 .show = s_show,
173};
174
175static int severities_coverage_open(struct inode *inode, struct file *file)
176{
177 return seq_open(file, &severities_seq_ops);
178}
179
180static ssize_t severities_coverage_write(struct file *file,
181 const char __user *ubuf,
182 size_t count, loff_t *ppos)
183{
184 int i;
185 for (i = 0; i < ARRAY_SIZE(severities); i++)
186 severities[i].covered = 0;
187 return count;
188}
189
190static const struct file_operations severities_coverage_fops = {
191 .open = severities_coverage_open,
192 .release = seq_release,
193 .read = seq_read,
194 .write = severities_coverage_write,
195};
196
197static int __init severities_debugfs_init(void)
198{
199 struct dentry *dmce = NULL, *fseverities_coverage = NULL;
200
201 dmce = mce_get_debugfs_dir();
202 if (dmce == NULL)
203 goto err_out;
204 fseverities_coverage = debugfs_create_file("severities-coverage",
205 0444, dmce, NULL,
206 &severities_coverage_fops);
207 if (fseverities_coverage == NULL)
208 goto err_out;
209
210 return 0;
211
212err_out:
213 return -ENOMEM;
214}
215late_initcall(severities_debugfs_init);
216#endif
217