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ea149b36 AK |
1 | /* |
2 | * Machine check injection support. | |
3 | * Copyright 2008 Intel Corporation. | |
4 | * | |
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 | |
8 | * of the License. | |
9 | * | |
10 | * Authors: | |
11 | * Andi Kleen | |
12 | * Ying Huang | |
13 | */ | |
98a9c8c3 | 14 | #include <linux/uaccess.h> |
ea149b36 AK |
15 | #include <linux/module.h> |
16 | #include <linux/timer.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/smp.h> | |
5b7e88ed HY |
21 | #include <linux/notifier.h> |
22 | #include <linux/kdebug.h> | |
23 | #include <linux/cpu.h> | |
24 | #include <linux/sched.h> | |
ea149b36 | 25 | #include <asm/mce.h> |
5b7e88ed | 26 | #include <asm/apic.h> |
ea149b36 AK |
27 | |
28 | /* Update fake mce registers on current CPU. */ | |
29 | static void inject_mce(struct mce *m) | |
30 | { | |
d620c67f | 31 | struct mce *i = &per_cpu(injectm, m->extcpu); |
ea149b36 AK |
32 | |
33 | /* Make sure noone reads partially written injectm */ | |
34 | i->finished = 0; | |
35 | mb(); | |
36 | m->finished = 0; | |
37 | /* First set the fields after finished */ | |
d620c67f | 38 | i->extcpu = m->extcpu; |
ea149b36 AK |
39 | mb(); |
40 | /* Now write record in order, finished last (except above) */ | |
41 | memcpy(i, m, sizeof(struct mce)); | |
42 | /* Finally activate it */ | |
43 | mb(); | |
44 | i->finished = 1; | |
45 | } | |
46 | ||
0dcc6685 | 47 | static void raise_poll(struct mce *m) |
5b7e88ed HY |
48 | { |
49 | unsigned long flags; | |
50 | mce_banks_t b; | |
51 | ||
52 | memset(&b, 0xff, sizeof(mce_banks_t)); | |
53 | local_irq_save(flags); | |
54 | machine_check_poll(0, &b); | |
55 | local_irq_restore(flags); | |
56 | m->finished = 0; | |
57 | } | |
58 | ||
0dcc6685 | 59 | static void raise_exception(struct mce *m, struct pt_regs *pregs) |
5b7e88ed HY |
60 | { |
61 | struct pt_regs regs; | |
62 | unsigned long flags; | |
63 | ||
64 | if (!pregs) { | |
65 | memset(®s, 0, sizeof(struct pt_regs)); | |
66 | regs.ip = m->ip; | |
67 | regs.cs = m->cs; | |
68 | pregs = ®s; | |
69 | } | |
70 | /* in mcheck exeception handler, irq will be disabled */ | |
71 | local_irq_save(flags); | |
72 | do_machine_check(pregs, 0); | |
73 | local_irq_restore(flags); | |
74 | m->finished = 0; | |
75 | } | |
76 | ||
6ac5c531 | 77 | static cpumask_var_t mce_inject_cpumask; |
5b7e88ed HY |
78 | |
79 | static int mce_raise_notify(struct notifier_block *self, | |
80 | unsigned long val, void *data) | |
81 | { | |
82 | struct die_args *args = (struct die_args *)data; | |
83 | int cpu = smp_processor_id(); | |
84 | struct mce *m = &__get_cpu_var(injectm); | |
6ac5c531 | 85 | if (val != DIE_NMI_IPI || !cpumask_test_cpu(cpu, mce_inject_cpumask)) |
5b7e88ed | 86 | return NOTIFY_DONE; |
6ac5c531 | 87 | cpumask_clear_cpu(cpu, mce_inject_cpumask); |
0dcc6685 HY |
88 | if (m->inject_flags & MCJ_EXCEPTION) |
89 | raise_exception(m, args->regs); | |
5b7e88ed | 90 | else if (m->status) |
0dcc6685 | 91 | raise_poll(m); |
5b7e88ed HY |
92 | return NOTIFY_STOP; |
93 | } | |
94 | ||
95 | static struct notifier_block mce_raise_nb = { | |
96 | .notifier_call = mce_raise_notify, | |
97 | .priority = 1000, | |
ea149b36 AK |
98 | }; |
99 | ||
100 | /* Inject mce on current CPU */ | |
14c0abf1 | 101 | static int raise_local(void) |
ea149b36 | 102 | { |
14c0abf1 | 103 | struct mce *m = &__get_cpu_var(injectm); |
5b7e88ed HY |
104 | int context = MCJ_CTX(m->inject_flags); |
105 | int ret = 0; | |
d620c67f | 106 | int cpu = m->extcpu; |
ea149b36 | 107 | |
0dcc6685 | 108 | if (m->inject_flags & MCJ_EXCEPTION) { |
ea149b36 | 109 | printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu); |
5b7e88ed HY |
110 | switch (context) { |
111 | case MCJ_CTX_IRQ: | |
112 | /* | |
113 | * Could do more to fake interrupts like | |
114 | * calling irq_enter, but the necessary | |
115 | * machinery isn't exported currently. | |
116 | */ | |
117 | /*FALL THROUGH*/ | |
118 | case MCJ_CTX_PROCESS: | |
0dcc6685 | 119 | raise_exception(m, NULL); |
5b7e88ed HY |
120 | break; |
121 | default: | |
122 | printk(KERN_INFO "Invalid MCE context\n"); | |
123 | ret = -EINVAL; | |
124 | } | |
ea149b36 | 125 | printk(KERN_INFO "MCE exception done on CPU %d\n", cpu); |
5b7e88ed | 126 | } else if (m->status) { |
ea149b36 | 127 | printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu); |
0dcc6685 | 128 | raise_poll(m); |
9ff36ee9 | 129 | mce_notify_irq(); |
5b7e88ed HY |
130 | printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu); |
131 | } else | |
132 | m->finished = 0; | |
133 | ||
134 | return ret; | |
135 | } | |
136 | ||
137 | static void raise_mce(struct mce *m) | |
138 | { | |
139 | int context = MCJ_CTX(m->inject_flags); | |
140 | ||
141 | inject_mce(m); | |
142 | ||
143 | if (context == MCJ_CTX_RANDOM) | |
144 | return; | |
145 | ||
146 | #ifdef CONFIG_X86_LOCAL_APIC | |
147 | if (m->inject_flags & MCJ_NMI_BROADCAST) { | |
148 | unsigned long start; | |
149 | int cpu; | |
150 | get_online_cpus(); | |
6ac5c531 RR |
151 | cpumask_copy(mce_inject_cpumask, cpu_online_mask); |
152 | cpumask_clear_cpu(get_cpu(), mce_inject_cpumask); | |
5b7e88ed HY |
153 | for_each_online_cpu(cpu) { |
154 | struct mce *mcpu = &per_cpu(injectm, cpu); | |
155 | if (!mcpu->finished || | |
156 | MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM) | |
6ac5c531 | 157 | cpumask_clear_cpu(cpu, mce_inject_cpumask); |
5b7e88ed | 158 | } |
6ac5c531 RR |
159 | if (!cpumask_empty(mce_inject_cpumask)) |
160 | apic->send_IPI_mask(mce_inject_cpumask, NMI_VECTOR); | |
5b7e88ed | 161 | start = jiffies; |
6ac5c531 | 162 | while (!cpumask_empty(mce_inject_cpumask)) { |
5b7e88ed HY |
163 | if (!time_before(jiffies, start + 2*HZ)) { |
164 | printk(KERN_ERR | |
165 | "Timeout waiting for mce inject NMI %lx\n", | |
6ac5c531 | 166 | *cpumask_bits(mce_inject_cpumask)); |
5b7e88ed HY |
167 | break; |
168 | } | |
169 | cpu_relax(); | |
170 | } | |
14c0abf1 | 171 | raise_local(); |
5b7e88ed HY |
172 | put_cpu(); |
173 | put_online_cpus(); | |
174 | } else | |
175 | #endif | |
14c0abf1 | 176 | raise_local(); |
ea149b36 AK |
177 | } |
178 | ||
179 | /* Error injection interface */ | |
180 | static ssize_t mce_write(struct file *filp, const char __user *ubuf, | |
181 | size_t usize, loff_t *off) | |
182 | { | |
ea149b36 AK |
183 | struct mce m; |
184 | ||
185 | if (!capable(CAP_SYS_ADMIN)) | |
186 | return -EPERM; | |
187 | /* | |
188 | * There are some cases where real MSR reads could slip | |
189 | * through. | |
190 | */ | |
191 | if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA)) | |
192 | return -EIO; | |
193 | ||
194 | if ((unsigned long)usize > sizeof(struct mce)) | |
195 | usize = sizeof(struct mce); | |
196 | if (copy_from_user(&m, ubuf, usize)) | |
197 | return -EFAULT; | |
198 | ||
d620c67f | 199 | if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu)) |
ea149b36 AK |
200 | return -EINVAL; |
201 | ||
ea149b36 AK |
202 | /* |
203 | * Need to give user space some time to set everything up, | |
204 | * so do it a jiffie or two later everywhere. | |
ea149b36 | 205 | */ |
5b7e88ed HY |
206 | schedule_timeout(2); |
207 | raise_mce(&m); | |
ea149b36 AK |
208 | return usize; |
209 | } | |
210 | ||
211 | static int inject_init(void) | |
212 | { | |
6ac5c531 RR |
213 | if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL)) |
214 | return -ENOMEM; | |
ea149b36 AK |
215 | printk(KERN_INFO "Machine check injector initialized\n"); |
216 | mce_chrdev_ops.write = mce_write; | |
5b7e88ed | 217 | register_die_notifier(&mce_raise_nb); |
ea149b36 AK |
218 | return 0; |
219 | } | |
220 | ||
221 | module_init(inject_init); | |
5706001a PA |
222 | /* |
223 | * Cannot tolerate unloading currently because we cannot | |
ea149b36 AK |
224 | * guarantee all openers of mce_chrdev will get a reference to us. |
225 | */ | |
226 | MODULE_LICENSE("GPL"); |