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@@ -0,0 +1,224 @@
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+/* Pseudo NMI support on sparc64 systems.
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+ *
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+ * Copyright (C) 2009 David S. Miller <davem@davemloft.net>
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+ *
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+ * The NMI watchdog support and infrastructure is based almost
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+ * entirely upon the x86 NMI support code.
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+ */
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+#include <linux/kernel.h>
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+#include <linux/param.h>
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+#include <linux/init.h>
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+#include <linux/percpu.h>
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+#include <linux/nmi.h>
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+#include <linux/module.h>
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+#include <linux/kprobes.h>
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+#include <linux/kernel_stat.h>
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+#include <linux/slab.h>
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+#include <linux/kdebug.h>
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+#include <linux/delay.h>
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+#include <linux/smp.h>
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+
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+#include <asm/ptrace.h>
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+#include <asm/local.h>
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+#include <asm/pcr.h>
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+
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+/* We don't have a real NMI on sparc64, but we can fake one
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+ * up using profiling counter overflow interrupts and interrupt
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+ * levels.
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+ *
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+ * The profile overflow interrupts at level 15, so we use
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+ * level 14 as our IRQ off level.
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+ */
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+
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+static int nmi_watchdog_active;
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+static int panic_on_timeout;
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+
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+int nmi_usable;
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+EXPORT_SYMBOL_GPL(nmi_usable);
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+
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+static unsigned int nmi_hz = HZ;
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+
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+static DEFINE_PER_CPU(unsigned int, last_irq_sum);
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+static DEFINE_PER_CPU(local_t, alert_counter);
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+static DEFINE_PER_CPU(int, nmi_touch);
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+
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+void touch_nmi_watchdog(void)
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+{
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+ if (nmi_watchdog_active) {
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+ int cpu;
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+
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+ for_each_present_cpu(cpu) {
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+ if (per_cpu(nmi_touch, cpu) != 1)
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+ per_cpu(nmi_touch, cpu) = 1;
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+ }
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+ }
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+
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+ touch_softlockup_watchdog();
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+}
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+EXPORT_SYMBOL(touch_nmi_watchdog);
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+
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+static void die_nmi(const char *str, struct pt_regs *regs, int do_panic)
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+{
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+ if (notify_die(DIE_NMIWATCHDOG, str, regs, 0,
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+ pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
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+ return;
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+
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+ console_verbose();
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+ bust_spinlocks(1);
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+
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+ printk(KERN_EMERG "%s", str);
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+ printk(" on CPU%d, ip %08lx, registers:\n",
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+ smp_processor_id(), regs->tpc);
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+ show_regs(regs);
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+
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+ bust_spinlocks(0);
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+
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+ if (do_panic || panic_on_oops)
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+ panic("Non maskable interrupt");
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+
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+ local_irq_enable();
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+ do_exit(SIGBUS);
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+}
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+
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+notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)
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+{
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+ unsigned int sum, touched = 0;
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+ int cpu = smp_processor_id();
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+
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+ clear_softint(1 << irq);
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+ pcr_ops->write(PCR_PIC_PRIV);
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+
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+ local_cpu_data().__nmi_count++;
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+
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+ if (notify_die(DIE_NMI, "nmi", regs, 0,
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+ pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
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+ touched = 1;
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+
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+ sum = kstat_cpu(cpu).irqs[0];
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+ if (__get_cpu_var(nmi_touch)) {
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+ __get_cpu_var(nmi_touch) = 0;
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+ touched = 1;
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+ }
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+ if (!touched && __get_cpu_var(last_irq_sum) == sum) {
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+ local_inc(&__get_cpu_var(alert_counter));
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+ if (local_read(&__get_cpu_var(alert_counter)) == 5 * nmi_hz)
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+ die_nmi("BUG: NMI Watchdog detected LOCKUP",
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+ regs, panic_on_timeout);
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+ } else {
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+ __get_cpu_var(last_irq_sum) = sum;
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+ local_set(&__get_cpu_var(alert_counter), 0);
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+ }
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+ if (nmi_usable) {
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+ write_pic(picl_value(nmi_hz));
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+ pcr_ops->write(pcr_enable);
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+ }
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+}
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+
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+static inline unsigned int get_nmi_count(int cpu)
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+{
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+ return cpu_data(cpu).__nmi_count;
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+}
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+
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+static int endflag __initdata;
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+
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+static __init void nmi_cpu_busy(void *data)
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+{
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+ local_irq_enable_in_hardirq();
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+ while (endflag == 0)
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+ mb();
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+}
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+
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+static void report_broken_nmi(int cpu, int *prev_nmi_count)
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+{
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+ printk(KERN_CONT "\n");
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+
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+ printk(KERN_WARNING
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+ "WARNING: CPU#%d: NMI appears to be stuck (%d->%d)!\n",
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+ cpu, prev_nmi_count[cpu], get_nmi_count(cpu));
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+
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+ printk(KERN_WARNING
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+ "Please report this to bugzilla.kernel.org,\n");
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+ printk(KERN_WARNING
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+ "and attach the output of the 'dmesg' command.\n");
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+
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+ nmi_usable = 0;
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+}
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+
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+static void stop_watchdog(void *unused)
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+{
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+ pcr_ops->write(PCR_PIC_PRIV);
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+}
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+
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+static int __init check_nmi_watchdog(void)
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+{
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+ unsigned int *prev_nmi_count;
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+ int cpu, err;
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+
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+ prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(unsigned int), GFP_KERNEL);
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+ if (!prev_nmi_count) {
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+ err = -ENOMEM;
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+ goto error;
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+ }
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+
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+ printk(KERN_INFO "Testing NMI watchdog ... ");
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+
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+ smp_call_function(nmi_cpu_busy, (void *)&endflag, 0);
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+
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+ for_each_possible_cpu(cpu)
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+ prev_nmi_count[cpu] = get_nmi_count(cpu);
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+ local_irq_enable();
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+ mdelay((20 * 1000) / nmi_hz); /* wait 20 ticks */
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+
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+ for_each_online_cpu(cpu) {
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+ if (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5)
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+ report_broken_nmi(cpu, prev_nmi_count);
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+ }
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+ endflag = 1;
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+ if (!nmi_usable) {
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+ kfree(prev_nmi_count);
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+ err = -ENODEV;
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+ goto error;
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+ }
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+ printk("OK.\n");
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+
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+ nmi_hz = 1;
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+
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+ kfree(prev_nmi_count);
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+ return 0;
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+error:
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+ on_each_cpu(stop_watchdog, NULL, 1);
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+ return err;
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+}
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+
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+static void start_watchdog(void *unused)
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+{
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+ pcr_ops->write(PCR_PIC_PRIV);
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+ write_pic(picl_value(nmi_hz));
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+
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+ pcr_ops->write(pcr_enable);
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+}
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+
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+void nmi_adjust_hz(unsigned int new_hz)
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+{
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+ nmi_hz = new_hz;
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+ on_each_cpu(start_watchdog, NULL, 1);
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+}
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+EXPORT_SYMBOL_GPL(nmi_adjust_hz);
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+
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+int __init nmi_init(void)
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+{
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+ nmi_usable = 1;
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+
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+ on_each_cpu(start_watchdog, NULL, 1);
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+
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+ return check_nmi_watchdog();
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+}
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+
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+static int __init setup_nmi_watchdog(char *str)
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+{
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+ if (!strncmp(str, "panic", 5))
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+ panic_on_timeout = 1;
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+
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+ return 0;
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+}
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+__setup("nmi_watchdog=", setup_nmi_watchdog);
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David S. Miller