2 * Machine check injection support.
3 * Copyright 2008 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
14 #include <linux/uaccess.h>
15 #include <linux/module.h>
16 #include <linux/timer.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
20 #include <linux/smp.h>
21 #include <linux/notifier.h>
22 #include <linux/kdebug.h>
23 #include <linux/cpu.h>
24 #include <linux/sched.h>
25 #include <linux/gfp.h>
30 /* Update fake mce registers on current CPU. */
31 static void inject_mce(struct mce *m)
33 struct mce *i = &per_cpu(injectm, m->extcpu);
35 /* Make sure no one reads partially written injectm */
39 /* First set the fields after finished */
40 i->extcpu = m->extcpu;
42 /* Now write record in order, finished last (except above) */
43 memcpy(i, m, sizeof(struct mce));
44 /* Finally activate it */
49 static void raise_poll(struct mce *m)
54 memset(&b, 0xff, sizeof(mce_banks_t));
55 local_irq_save(flags);
56 machine_check_poll(0, &b);
57 local_irq_restore(flags);
61 static void raise_exception(struct mce *m, struct pt_regs *pregs)
67 memset(®s, 0, sizeof(struct pt_regs));
72 /* in mcheck exeception handler, irq will be disabled */
73 local_irq_save(flags);
74 do_machine_check(pregs, 0);
75 local_irq_restore(flags);
79 static cpumask_var_t mce_inject_cpumask;
81 static int mce_raise_notify(struct notifier_block *self,
82 unsigned long val, void *data)
84 struct die_args *args = (struct die_args *)data;
85 int cpu = smp_processor_id();
86 struct mce *m = &__get_cpu_var(injectm);
87 if (val != DIE_NMI || !cpumask_test_cpu(cpu, mce_inject_cpumask))
89 cpumask_clear_cpu(cpu, mce_inject_cpumask);
90 if (m->inject_flags & MCJ_EXCEPTION)
91 raise_exception(m, args->regs);
97 static struct notifier_block mce_raise_nb = {
98 .notifier_call = mce_raise_notify,
99 .priority = NMI_LOCAL_NORMAL_PRIOR,
102 /* Inject mce on current CPU */
103 static int raise_local(void)
105 struct mce *m = &__get_cpu_var(injectm);
106 int context = MCJ_CTX(m->inject_flags);
110 if (m->inject_flags & MCJ_EXCEPTION) {
111 printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
115 * Could do more to fake interrupts like
116 * calling irq_enter, but the necessary
117 * machinery isn't exported currently.
120 case MCJ_CTX_PROCESS:
121 raise_exception(m, NULL);
124 printk(KERN_INFO "Invalid MCE context\n");
127 printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
128 } else if (m->status) {
129 printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
132 printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu);
139 static void raise_mce(struct mce *m)
141 int context = MCJ_CTX(m->inject_flags);
145 if (context == MCJ_CTX_RANDOM)
148 #ifdef CONFIG_X86_LOCAL_APIC
149 if (m->inject_flags & MCJ_NMI_BROADCAST) {
153 cpumask_copy(mce_inject_cpumask, cpu_online_mask);
154 cpumask_clear_cpu(get_cpu(), mce_inject_cpumask);
155 for_each_online_cpu(cpu) {
156 struct mce *mcpu = &per_cpu(injectm, cpu);
157 if (!mcpu->finished ||
158 MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM)
159 cpumask_clear_cpu(cpu, mce_inject_cpumask);
161 if (!cpumask_empty(mce_inject_cpumask))
162 apic->send_IPI_mask(mce_inject_cpumask, NMI_VECTOR);
164 while (!cpumask_empty(mce_inject_cpumask)) {
165 if (!time_before(jiffies, start + 2*HZ)) {
167 "Timeout waiting for mce inject NMI %lx\n",
168 *cpumask_bits(mce_inject_cpumask));
181 /* Error injection interface */
182 static ssize_t mce_write(struct file *filp, const char __user *ubuf,
183 size_t usize, loff_t *off)
187 if (!capable(CAP_SYS_ADMIN))
190 * There are some cases where real MSR reads could slip
193 if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
196 if ((unsigned long)usize > sizeof(struct mce))
197 usize = sizeof(struct mce);
198 if (copy_from_user(&m, ubuf, usize))
201 if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
205 * Need to give user space some time to set everything up,
206 * so do it a jiffie or two later everywhere.
213 static int inject_init(void)
215 if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
217 printk(KERN_INFO "Machine check injector initialized\n");
218 mce_chrdev_ops.write = mce_write;
219 register_die_notifier(&mce_raise_nb);
223 module_init(inject_init);
225 * Cannot tolerate unloading currently because we cannot
226 * guarantee all openers of mce_chrdev will get a reference to us.
228 MODULE_LICENSE("GPL");