315 строки
7.0 KiB
C
315 строки
7.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* 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 1;
|
|
}
|
|
__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);
|
|
}
|