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Diffstat (limited to 'arch/sparc/kernel/nmi.c')
-rw-r--r--arch/sparc/kernel/nmi.c140
1 files changed, 94 insertions, 46 deletions
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
index f3577223c86..33709455691 100644
--- a/arch/sparc/kernel/nmi.c
+++ b/arch/sparc/kernel/nmi.c
@@ -10,18 +10,21 @@
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/nmi.h>
-#include <linux/module.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/local.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.
@@ -30,21 +33,27 @@
* level 14 as our IRQ off level.
*/
-static int nmi_watchdog_active;
static int panic_on_timeout;
-int nmi_usable;
-EXPORT_SYMBOL_GPL(nmi_usable);
+/* 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(local_t, alert_counter);
+static DEFINE_PER_CPU(long, alert_counter);
static DEFINE_PER_CPU(int, nmi_touch);
void touch_nmi_watchdog(void)
{
- if (nmi_watchdog_active) {
+ if (atomic_read(&nmi_active)) {
int cpu;
for_each_present_cpu(cpu) {
@@ -59,60 +68,59 @@ 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;
- console_verbose();
- bust_spinlocks(1);
-
- printk(KERN_EMERG "%s", str);
- printk(" on CPU%d, ip %08lx, registers:\n",
- smp_processor_id(), regs->tpc);
- show_regs(regs);
- dump_stack();
-
- bust_spinlocks(0);
-
if (do_panic || panic_on_oops)
- panic("Non maskable interrupt");
-
- local_irq_enable();
- do_exit(SIGBUS);
+ 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;
- int cpu = smp_processor_id();
+ void *orig_sp;
clear_softint(1 << irq);
- pcr_ops->write(PCR_PIC_PRIV);
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 = kstat_irqs_cpu(0, cpu);
+ 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) {
- local_inc(&__get_cpu_var(alert_counter));
- if (local_read(&__get_cpu_var(alert_counter)) == 5 * nmi_hz)
+ __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;
- local_set(&__get_cpu_var(alert_counter), 0);
+ __this_cpu_write(alert_counter, 0);
}
- if (nmi_usable) {
- write_pic(picl_value(nmi_hz));
- pcr_ops->write(pcr_enable);
+ 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)
@@ -120,8 +128,6 @@ static inline unsigned int get_nmi_count(int cpu)
return cpu_data(cpu).__nmi_count;
}
-static int endflag __initdata;
-
static __init void nmi_cpu_busy(void *data)
{
local_irq_enable_in_hardirq();
@@ -142,12 +148,15 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count)
printk(KERN_WARNING
"and attach the output of the 'dmesg' command.\n");
- nmi_usable = 0;
+ per_cpu(wd_enabled, cpu) = 0;
+ atomic_dec(&nmi_active);
}
-static void stop_watchdog(void *unused)
+void stop_nmi_watchdog(void *unused)
{
- pcr_ops->write(PCR_PIC_PRIV);
+ 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)
@@ -155,6 +164,9 @@ 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;
@@ -171,12 +183,15 @@ static int __init check_nmi_watchdog(void)
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 (!nmi_usable) {
+ if (!atomic_read(&nmi_active)) {
kfree(prev_nmi_count);
+ atomic_set(&nmi_active, -1);
err = -ENODEV;
goto error;
}
@@ -187,32 +202,65 @@ static int __init check_nmi_watchdog(void)
kfree(prev_nmi_count);
return 0;
error:
- on_each_cpu(stop_watchdog, NULL, 1);
+ on_each_cpu(stop_nmi_watchdog, NULL, 1);
return err;
}
-static void start_watchdog(void *unused)
+void start_nmi_watchdog(void *unused)
{
- pcr_ops->write(PCR_PIC_PRIV);
- write_pic(picl_value(nmi_hz));
+ __get_cpu_var(wd_enabled) = 1;
+ atomic_inc(&nmi_active);
- pcr_ops->write(pcr_enable);
+ 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(start_watchdog, NULL, 1);
+ 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)
{
- nmi_usable = 1;
+ int err;
- on_each_cpu(start_watchdog, NULL, 1);
+ on_each_cpu(start_nmi_watchdog, NULL, 1);
- return check_nmi_watchdog();
+ 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)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 14:36:10 +0000