v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
new file mode 100644
index 0000000..8babbeb
--- /dev/null
+++ b/arch/sparc/kernel/nmi.c
@@ -0,0 +1,313 @@
+/* Pseudo NMI support on sparc64 systems.
+ *
+ * Copyright (C) 2009 David S. Miller <davem@davemloft.net>
+ *
+ * The NMI watchdog support and infrastructure is based almost
+ * entirely upon the x86 NMI support code.
+ */
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/nmi.h>
+#include <linux/export.h>
+#include <linux/kprobes.h>
+#include <linux/kernel_stat.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+#include <linux/kdebug.h>
+#include <linux/delay.h>
+#include <linux/smp.h>
+
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
+#include <asm/pcr.h>
+
+#include "kstack.h"
+
+/* We don't have a real NMI on sparc64, but we can fake one
+ * up using profiling counter overflow interrupts and interrupt
+ * levels.
+ *
+ * The profile overflow interrupts at level 15, so we use
+ * level 14 as our IRQ off level.
+ */
+
+static int panic_on_timeout;
+
+/* nmi_active:
+ * >0: the NMI watchdog is active, but can be disabled
+ * <0: the NMI watchdog has not been set up, and cannot be enabled
+ * 0: the NMI watchdog is disabled, but can be enabled
+ */
+atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
+EXPORT_SYMBOL(nmi_active);
+static int nmi_init_done;
+static unsigned int nmi_hz = HZ;
+static DEFINE_PER_CPU(short, wd_enabled);
+static int endflag __initdata;
+
+static DEFINE_PER_CPU(unsigned int, last_irq_sum);
+static DEFINE_PER_CPU(long, alert_counter);
+static DEFINE_PER_CPU(int, nmi_touch);
+
+void arch_touch_nmi_watchdog(void)
+{
+ if (atomic_read(&nmi_active)) {
+ int cpu;
+
+ for_each_present_cpu(cpu) {
+ if (per_cpu(nmi_touch, cpu) != 1)
+ per_cpu(nmi_touch, cpu) = 1;
+ }
+ }
+}
+EXPORT_SYMBOL(arch_touch_nmi_watchdog);
+
+static void die_nmi(const char *str, struct pt_regs *regs, int do_panic)
+{
+ int this_cpu = smp_processor_id();
+
+ if (notify_die(DIE_NMIWATCHDOG, str, regs, 0,
+ pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
+ return;
+
+ if (do_panic || panic_on_oops)
+ panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ else
+ WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+}
+
+notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)
+{
+ unsigned int sum, touched = 0;
+ void *orig_sp;
+
+ clear_softint(1 << irq);
+
+ local_cpu_data().__nmi_count++;
+
+ nmi_enter();
+
+ orig_sp = set_hardirq_stack();
+
+ if (notify_die(DIE_NMI, "nmi", regs, 0,
+ pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
+ touched = 1;
+ else
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
+
+ sum = local_cpu_data().irq0_irqs;
+ if (__this_cpu_read(nmi_touch)) {
+ __this_cpu_write(nmi_touch, 0);
+ touched = 1;
+ }
+ if (!touched && __this_cpu_read(last_irq_sum) == sum) {
+ __this_cpu_inc(alert_counter);
+ if (__this_cpu_read(alert_counter) == 30 * nmi_hz)
+ die_nmi("BUG: NMI Watchdog detected LOCKUP",
+ regs, panic_on_timeout);
+ } else {
+ __this_cpu_write(last_irq_sum, sum);
+ __this_cpu_write(alert_counter, 0);
+ }
+ if (__this_cpu_read(wd_enabled)) {
+ pcr_ops->write_pic(0, pcr_ops->nmi_picl_value(nmi_hz));
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_enable);
+ }
+
+ restore_hardirq_stack(orig_sp);
+
+ nmi_exit();
+}
+
+static inline unsigned int get_nmi_count(int cpu)
+{
+ return cpu_data(cpu).__nmi_count;
+}
+
+static __init void nmi_cpu_busy(void *data)
+{
+ while (endflag == 0)
+ mb();
+}
+
+static void report_broken_nmi(int cpu, int *prev_nmi_count)
+{
+ printk(KERN_CONT "\n");
+
+ printk(KERN_WARNING
+ "WARNING: CPU#%d: NMI appears to be stuck (%d->%d)!\n",
+ cpu, prev_nmi_count[cpu], get_nmi_count(cpu));
+
+ printk(KERN_WARNING
+ "Please report this to bugzilla.kernel.org,\n");
+ printk(KERN_WARNING
+ "and attach the output of the 'dmesg' command.\n");
+
+ per_cpu(wd_enabled, cpu) = 0;
+ atomic_dec(&nmi_active);
+}
+
+void stop_nmi_watchdog(void *unused)
+{
+ if (!__this_cpu_read(wd_enabled))
+ return;
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
+ __this_cpu_write(wd_enabled, 0);
+ atomic_dec(&nmi_active);
+}
+
+static int __init check_nmi_watchdog(void)
+{
+ unsigned int *prev_nmi_count;
+ int cpu, err;
+
+ if (!atomic_read(&nmi_active))
+ return 0;
+
+ prev_nmi_count = kmalloc_array(nr_cpu_ids, sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!prev_nmi_count) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ printk(KERN_INFO "Testing NMI watchdog ... ");
+
+ smp_call_function(nmi_cpu_busy, (void *)&endflag, 0);
+
+ for_each_possible_cpu(cpu)
+ prev_nmi_count[cpu] = get_nmi_count(cpu);
+ local_irq_enable();
+ mdelay((20 * 1000) / nmi_hz); /* wait 20 ticks */
+
+ for_each_online_cpu(cpu) {
+ if (!per_cpu(wd_enabled, cpu))
+ continue;
+ if (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5)
+ report_broken_nmi(cpu, prev_nmi_count);
+ }
+ endflag = 1;
+ if (!atomic_read(&nmi_active)) {
+ kfree(prev_nmi_count);
+ atomic_set(&nmi_active, -1);
+ err = -ENODEV;
+ goto error;
+ }
+ printk("OK.\n");
+
+ nmi_hz = 1;
+
+ kfree(prev_nmi_count);
+ return 0;
+error:
+ on_each_cpu(stop_nmi_watchdog, NULL, 1);
+ return err;
+}
+
+void start_nmi_watchdog(void *unused)
+{
+ if (__this_cpu_read(wd_enabled))
+ return;
+
+ __this_cpu_write(wd_enabled, 1);
+ atomic_inc(&nmi_active);
+
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
+ pcr_ops->write_pic(0, pcr_ops->nmi_picl_value(nmi_hz));
+
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_enable);
+}
+
+static void nmi_adjust_hz_one(void *unused)
+{
+ if (!__this_cpu_read(wd_enabled))
+ return;
+
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
+ pcr_ops->write_pic(0, pcr_ops->nmi_picl_value(nmi_hz));
+
+ pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_enable);
+}
+
+void nmi_adjust_hz(unsigned int new_hz)
+{
+ nmi_hz = new_hz;
+ on_each_cpu(nmi_adjust_hz_one, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(nmi_adjust_hz);
+
+static int nmi_shutdown(struct notifier_block *nb, unsigned long cmd, void *p)
+{
+ on_each_cpu(stop_nmi_watchdog, NULL, 1);
+ return 0;
+}
+
+static struct notifier_block nmi_reboot_notifier = {
+ .notifier_call = nmi_shutdown,
+};
+
+int __init nmi_init(void)
+{
+ int err;
+
+ on_each_cpu(start_nmi_watchdog, NULL, 1);
+
+ err = check_nmi_watchdog();
+ if (!err) {
+ err = register_reboot_notifier(&nmi_reboot_notifier);
+ if (err) {
+ on_each_cpu(stop_nmi_watchdog, NULL, 1);
+ atomic_set(&nmi_active, -1);
+ }
+ }
+
+ nmi_init_done = 1;
+
+ return err;
+}
+
+static int __init setup_nmi_watchdog(char *str)
+{
+ if (!strncmp(str, "panic", 5))
+ panic_on_timeout = 1;
+
+ return 0;
+}
+__setup("nmi_watchdog=", setup_nmi_watchdog);
+
+/*
+ * sparc specific NMI watchdog enable function.
+ * Enables watchdog if it is not enabled already.
+ */
+int watchdog_nmi_enable(unsigned int cpu)
+{
+ if (atomic_read(&nmi_active) == -1) {
+ pr_warn("NMI watchdog cannot be enabled or disabled\n");
+ return -1;
+ }
+
+ /*
+ * watchdog thread could start even before nmi_init is called.
+ * Just Return in that case. Let nmi_init finish the init
+ * process first.
+ */
+ if (!nmi_init_done)
+ return 0;
+
+ smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1);
+
+ return 0;
+}
+/*
+ * sparc specific NMI watchdog disable function.
+ * Disables watchdog if it is not disabled already.
+ */
+void watchdog_nmi_disable(unsigned int cpu)
+{
+ if (atomic_read(&nmi_active) == -1)
+ pr_warn_once("NMI watchdog cannot be enabled or disabled\n");
+ else
+ smp_call_function_single(cpu, stop_nmi_watchdog, NULL, 1);
+}