forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
314 lines
7.0 KiB
314 lines
7.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* Pseudo NMI support on sparc64 systems. |
|
* |
|
* Copyright (C) 2009 David S. Miller <[email protected]> |
|
* |
|
* 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); |
|
}
|
|
|