WSL2-Linux-Kernel/arch/sparc/kernel/nmi.c

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/* 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>
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 14:02:48 +04:00
#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 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 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;
}
}
touch_softlockup_watchdog();
}
EXPORT_SYMBOL(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 (__get_cpu_var(nmi_touch)) {
__get_cpu_var(nmi_touch) = 0;
touched = 1;
}
if (!touched && __get_cpu_var(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 {
__get_cpu_var(last_irq_sum) = sum;
__this_cpu_write(alert_counter, 0);
}
if (__get_cpu_var(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)
{
local_irq_enable_in_hardirq();
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)
{
pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
__get_cpu_var(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(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)
{
__get_cpu_var(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 (!__get_cpu_var(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);
}
}
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);