--- /dev/null
+/*
+ * Machine check injection support.
+ * Copyright 2008 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.
+ *
+ * Authors:
+ * Andi Kleen
+ * Ying Huang
+ */
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/preempt.h>
+#include <linux/smp.h>
+#include <linux/notifier.h>
+#include <linux/kdebug.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <asm/mce.h>
+#include <asm/apic.h>
+#include <asm/nmi.h>
+
+/* Update fake mce registers on current CPU. */
+static void inject_mce(struct mce *m)
+{
+ struct mce *i = &per_cpu(injectm, m->extcpu);
+
+ /* Make sure no one reads partially written injectm */
+ i->finished = 0;
+ mb();
+ m->finished = 0;
+ /* First set the fields after finished */
+ i->extcpu = m->extcpu;
+ mb();
+ /* Now write record in order, finished last (except above) */
+ memcpy(i, m, sizeof(struct mce));
+ /* Finally activate it */
+ mb();
+ i->finished = 1;
+}
+
+static void raise_poll(struct mce *m)
+{
+ unsigned long flags;
+ mce_banks_t b;
+
+ memset(&b, 0xff, sizeof(mce_banks_t));
+ local_irq_save(flags);
+ machine_check_poll(0, &b);
+ local_irq_restore(flags);
+ m->finished = 0;
+}
+
+static void raise_exception(struct mce *m, struct pt_regs *pregs)
+{
+ struct pt_regs regs;
+ unsigned long flags;
+
+ if (!pregs) {
+ memset(®s, 0, sizeof(struct pt_regs));
+ regs.ip = m->ip;
+ regs.cs = m->cs;
+ pregs = ®s;
+ }
+ /* in mcheck exeception handler, irq will be disabled */
+ local_irq_save(flags);
+ do_machine_check(pregs, 0);
+ local_irq_restore(flags);
+ m->finished = 0;
+}
+
+static cpumask_var_t mce_inject_cpumask;
+static DEFINE_MUTEX(mce_inject_mutex);
+
+static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
+{
+ int cpu = smp_processor_id();
+ struct mce *m = this_cpu_ptr(&injectm);
+ if (!cpumask_test_cpu(cpu, mce_inject_cpumask))
+ return NMI_DONE;
+ cpumask_clear_cpu(cpu, mce_inject_cpumask);
+ if (m->inject_flags & MCJ_EXCEPTION)
+ raise_exception(m, regs);
+ else if (m->status)
+ raise_poll(m);
+ return NMI_HANDLED;
+}
+
+static void mce_irq_ipi(void *info)
+{
+ int cpu = smp_processor_id();
+ struct mce *m = this_cpu_ptr(&injectm);
+
+ if (cpumask_test_cpu(cpu, mce_inject_cpumask) &&
+ m->inject_flags & MCJ_EXCEPTION) {
+ cpumask_clear_cpu(cpu, mce_inject_cpumask);
+ raise_exception(m, NULL);
+ }
+}
+
+/* Inject mce on current CPU */
+static int raise_local(void)
+{
+ struct mce *m = this_cpu_ptr(&injectm);
+ int context = MCJ_CTX(m->inject_flags);
+ int ret = 0;
+ int cpu = m->extcpu;
+
+ if (m->inject_flags & MCJ_EXCEPTION) {
+ printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
+ switch (context) {
+ case MCJ_CTX_IRQ:
+ /*
+ * Could do more to fake interrupts like
+ * calling irq_enter, but the necessary
+ * machinery isn't exported currently.
+ */
+ /*FALL THROUGH*/
+ case MCJ_CTX_PROCESS:
+ raise_exception(m, NULL);
+ break;
+ default:
+ printk(KERN_INFO "Invalid MCE context\n");
+ ret = -EINVAL;
+ }
+ printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
+ } else if (m->status) {
+ printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
+ raise_poll(m);
+ mce_notify_irq();
+ printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu);
+ } else
+ m->finished = 0;
+
+ return ret;
+}
+
+static void raise_mce(struct mce *m)
+{
+ int context = MCJ_CTX(m->inject_flags);
+
+ inject_mce(m);
+
+ if (context == MCJ_CTX_RANDOM)
+ return;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ if (m->inject_flags & (MCJ_IRQ_BROADCAST | MCJ_NMI_BROADCAST)) {
+ unsigned long start;
+ int cpu;
+
+ get_online_cpus();
+ cpumask_copy(mce_inject_cpumask, cpu_online_mask);
+ cpumask_clear_cpu(get_cpu(), mce_inject_cpumask);
+ for_each_online_cpu(cpu) {
+ struct mce *mcpu = &per_cpu(injectm, cpu);
+ if (!mcpu->finished ||
+ MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM)
+ cpumask_clear_cpu(cpu, mce_inject_cpumask);
+ }
+ if (!cpumask_empty(mce_inject_cpumask)) {
+ if (m->inject_flags & MCJ_IRQ_BROADCAST) {
+ /*
+ * don't wait because mce_irq_ipi is necessary
+ * to be sync with following raise_local
+ */
+ preempt_disable();
+ smp_call_function_many(mce_inject_cpumask,
+ mce_irq_ipi, NULL, 0);
+ preempt_enable();
+ } else if (m->inject_flags & MCJ_NMI_BROADCAST)
+ apic->send_IPI_mask(mce_inject_cpumask,
+ NMI_VECTOR);
+ }
+ start = jiffies;
+ while (!cpumask_empty(mce_inject_cpumask)) {
+ if (!time_before(jiffies, start + 2*HZ)) {
+ printk(KERN_ERR
+ "Timeout waiting for mce inject %lx\n",
+ *cpumask_bits(mce_inject_cpumask));
+ break;
+ }
+ cpu_relax();
+ }
+ raise_local();
+ put_cpu();
+ put_online_cpus();
+ } else
+#endif
+ {
+ preempt_disable();
+ raise_local();
+ preempt_enable();
+ }
+}
+
+/* Error injection interface */
+static ssize_t mce_write(struct file *filp, const char __user *ubuf,
+ size_t usize, loff_t *off)
+{
+ struct mce m;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ /*
+ * There are some cases where real MSR reads could slip
+ * through.
+ */
+ if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
+ return -EIO;
+
+ if ((unsigned long)usize > sizeof(struct mce))
+ usize = sizeof(struct mce);
+ if (copy_from_user(&m, ubuf, usize))
+ return -EFAULT;
+
+ if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
+ return -EINVAL;
+
+ /*
+ * Need to give user space some time to set everything up,
+ * so do it a jiffie or two later everywhere.
+ */
+ schedule_timeout(2);
+
+ mutex_lock(&mce_inject_mutex);
+ raise_mce(&m);
+ mutex_unlock(&mce_inject_mutex);
+ return usize;
+}
+
+static int inject_init(void)
+{
+ if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
+ return -ENOMEM;
+ printk(KERN_INFO "Machine check injector initialized\n");
+ register_mce_write_callback(mce_write);
+ register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
+ "mce_notify");
+ return 0;
+}
+
+module_init(inject_init);
+/*
+ * Cannot tolerate unloading currently because we cannot
+ * guarantee all openers of mce_chrdev will get a reference to us.
+ */
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff