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sparc64: Implement NMI watchdog on capable cpus.

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Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2009-01-29 21:22:47 -08:00
parent c3cf5e8cc5
commit e5553a6d04
10 changed files with 319 additions and 173 deletions
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2
arch/sparc/include/asm/cpudata_64.h
View File

@ -17,7 +17,7 @@
typedef struct {
/* Dcache line 1 */
unsigned int __softirq_pending; /* must be 1st, see rtrap.S */
unsigned int __pad0;
unsigned int __nmi_count;
unsigned long clock_tick; /* %tick's per second */
unsigned long __pad;
unsigned int __pad1;

4
arch/sparc/include/asm/irq_64.h
View File

@ -66,9 +66,6 @@ extern void virt_irq_free(unsigned int virt_irq);
extern void __init init_IRQ(void);
extern void fixup_irqs(void);
extern int register_perfctr_intr(void (*handler)(struct pt_regs *));
extern void release_perfctr_intr(void (*handler)(struct pt_regs *));
static inline void set_softint(unsigned long bits)
{
__asm__ __volatile__("wr %0, 0x0, %%set_softint"
@ -98,5 +95,6 @@ void __trigger_all_cpu_backtrace(void);
extern void *hardirq_stack[NR_CPUS];
extern void *softirq_stack[NR_CPUS];
#define __ARCH_HAS_DO_SOFTIRQ
#define ARCH_HAS_NMI_WATCHDOG
#endif

2
arch/sparc/include/asm/kdebug_64.h
View File

@ -14,6 +14,8 @@ enum die_val {
DIE_TRAP,
DIE_TRAP_TL1,
DIE_CALL,
DIE_NMI,
DIE_NMIWATCHDOG,
};
#endif

10
arch/sparc/include/asm/nmi.h Normal file
View File

@ -0,0 +1,10 @@
#ifndef __NMI_H
#define __NMI_H
extern int __init nmi_init(void);
extern void perfctr_irq(int irq, struct pt_regs *regs);
extern void nmi_adjust_hz(unsigned int new_hz);
extern int nmi_usable;
#endif /* __NMI_H */

16
arch/sparc/include/asm/pcr.h
View File

@ -27,4 +27,20 @@ extern void schedule_deferred_pcr_work(void);
#define PCR_N2_SL1_SHIFT 27
#define PCR_N2_OV1 0x80000000
extern unsigned int picl_shift;
/* In order to commonize as much of the implementation as
* possible, we use PICH as our counter. Mostly this is
* to accomodate Niagara-1 which can only count insn cycles
* in PICH.
*/
static inline u64 picl_value(unsigned int nmi_hz)
{
u32 delta = local_cpu_data().clock_tick / (nmi_hz << picl_shift);
return ((u64)((0 - delta) & 0xffffffff)) << 32;
}
extern u64 pcr_enable;
#endif /* __PCR_H */

1
arch/sparc/kernel/Makefile
View File

@ -53,6 +53,7 @@ obj-$(CONFIG_SPARC64) += hvapi.o
obj-$(CONFIG_SPARC64) += sstate.o
obj-$(CONFIG_SPARC64) += mdesc.o
obj-$(CONFIG_SPARC64) += pcr.o
obj-$(CONFIG_SPARC64) += nmi.o
# sparc32 do not use GENERIC_HARDIRQS but uses the generic devres implementation
obj-$(CONFIG_SPARC32) += devres.o

68
arch/sparc/kernel/irq_64.c
View File

@ -196,6 +196,11 @@ int show_interrupts(struct seq_file *p, void *v)
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == NR_IRQS) {
seq_printf(p, "NMI: ");
for_each_online_cpu(j)
seq_printf(p, "%10u ", cpu_data(j).__nmi_count);
seq_printf(p, " Non-maskable interrupts\n");
}
return 0;
}
@ -778,69 +783,6 @@ void do_softirq(void)
local_irq_restore(flags);
}
static void unhandled_perf_irq(struct pt_regs *regs)
{
unsigned long pcr, pic;
read_pcr(pcr);
read_pic(pic);
write_pcr(0);
printk(KERN_EMERG "CPU %d: Got unexpected perf counter IRQ.\n",
smp_processor_id());
printk(KERN_EMERG "CPU %d: PCR[%016lx] PIC[%016lx]\n",
smp_processor_id(), pcr, pic);
}
/* Almost a direct copy of the powerpc PMC code. */
static DEFINE_SPINLOCK(perf_irq_lock);
static void *perf_irq_owner_caller; /* mostly for debugging */
static void (*perf_irq)(struct pt_regs *regs) = unhandled_perf_irq;
/* Invoked from level 15 PIL handler in trap table. */
void perfctr_irq(int irq, struct pt_regs *regs)
{
clear_softint(1 << irq);
perf_irq(regs);
}
int register_perfctr_intr(void (*handler)(struct pt_regs *))
{
int ret;
if (!handler)
return -EINVAL;
spin_lock(&perf_irq_lock);
if (perf_irq != unhandled_perf_irq) {
printk(KERN_WARNING "register_perfctr_intr: "
"perf IRQ busy (reserved by caller %p)\n",
perf_irq_owner_caller);
ret = -EBUSY;
goto out;
}
perf_irq_owner_caller = __builtin_return_address(0);
perf_irq = handler;
ret = 0;
out:
spin_unlock(&perf_irq_lock);
return ret;
}
EXPORT_SYMBOL_GPL(register_perfctr_intr);
void release_perfctr_intr(void (*handler)(struct pt_regs *))
{
spin_lock(&perf_irq_lock);
perf_irq_owner_caller = NULL;
perf_irq = unhandled_perf_irq;
spin_unlock(&perf_irq_lock);
}
EXPORT_SYMBOL_GPL(release_perfctr_intr);
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
{

224
arch/sparc/kernel/nmi.c Normal file
View File

@ -0,0 +1,224 @@
/* 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/module.h>
#include <linux/kprobes.h>
#include <linux/kernel_stat.h>
#include <linux/slab.h>
#include <linux/kdebug.h>
#include <linux/delay.h>
#include <linux/smp.h>
#include <asm/ptrace.h>
#include <asm/local.h>
#include <asm/pcr.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 nmi_watchdog_active;
static int panic_on_timeout;
int nmi_usable;
EXPORT_SYMBOL_GPL(nmi_usable);
static unsigned int nmi_hz = HZ;
static DEFINE_PER_CPU(unsigned int, last_irq_sum);
static DEFINE_PER_CPU(local_t, alert_counter);
static DEFINE_PER_CPU(int, nmi_touch);
void touch_nmi_watchdog(void)
{
if (nmi_watchdog_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)
{
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);
bust_spinlocks(0);
if (do_panic || panic_on_oops)
panic("Non maskable interrupt");
local_irq_enable();
do_exit(SIGBUS);
}
notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)
{
unsigned int sum, touched = 0;
int cpu = smp_processor_id();
clear_softint(1 << irq);
pcr_ops->write(PCR_PIC_PRIV);
local_cpu_data().__nmi_count++;
if (notify_die(DIE_NMI, "nmi", regs, 0,
pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
touched = 1;
sum = kstat_cpu(cpu).irqs[0];
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)
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);
}
if (nmi_usable) {
write_pic(picl_value(nmi_hz));
pcr_ops->write(pcr_enable);
}
}
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();
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");
nmi_usable = 0;
}
static void stop_watchdog(void *unused)
{
pcr_ops->write(PCR_PIC_PRIV);
}
static int __init check_nmi_watchdog(void)
{
unsigned int *prev_nmi_count;
int cpu, err;
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 (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5)
report_broken_nmi(cpu, prev_nmi_count);
}
endflag = 1;
if (!nmi_usable) {
kfree(prev_nmi_count);
err = -ENODEV;
goto error;
}
printk("OK.\n");
nmi_hz = 1;
kfree(prev_nmi_count);
return 0;
error:
on_each_cpu(stop_watchdog, NULL, 1);
return err;
}
static void start_watchdog(void *unused)
{
pcr_ops->write(PCR_PIC_PRIV);
write_pic(picl_value(nmi_hz));
pcr_ops->write(pcr_enable);
}
void nmi_adjust_hz(unsigned int new_hz)
{
nmi_hz = new_hz;
on_each_cpu(start_watchdog, NULL, 1);
}
EXPORT_SYMBOL_GPL(nmi_adjust_hz);
int __init nmi_init(void)
{
nmi_usable = 1;
on_each_cpu(start_watchdog, NULL, 1);
return check_nmi_watchdog();
}
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);

17
arch/sparc/kernel/pcr.c
View File

@ -9,12 +9,22 @@
#include <asm/pil.h>
#include <asm/pcr.h>
#include <asm/nmi.h>
/* This code is shared between various users of the performance
* counters. Users will be oprofile, pseudo-NMI watchdog, and the
* perf_counter support layer.
*/
#define PCR_SUN4U_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE)
#define PCR_N2_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE | \
PCR_N2_TOE_OV1 | \
(2 << PCR_N2_SL1_SHIFT) | \
(0xff << PCR_N2_MASK1_SHIFT))
u64 pcr_enable;
unsigned int picl_shift;
/* Performance counter interrupts run unmasked at PIL level 15.
* Therefore we can't do things like wakeups and other work
* that expects IRQ disabling to be adhered to in locking etc.
@ -117,12 +127,15 @@ int __init pcr_arch_init(void)
switch (tlb_type) {
case hypervisor:
pcr_ops = &n2_pcr_ops;
pcr_enable = PCR_N2_ENABLE;
picl_shift = 2;
break;
case spitfire:
case cheetah:
case cheetah_plus:
case spitfire:
pcr_ops = &direct_pcr_ops;
pcr_enable = PCR_SUN4U_ENABLE;
break;
default:
@ -130,7 +143,7 @@ int __init pcr_arch_init(void)
goto out_unregister;
}
return 0;
return nmi_init();
out_unregister:
unregister_perf_hsvc();

148
arch/sparc/oprofile/init.c
View File

@ -13,117 +13,57 @@
#include <linux/init.h>
#ifdef CONFIG_SPARC64
#include <asm/hypervisor.h>
#include <asm/spitfire.h>
#include <asm/cpudata.h>
#include <asm/irq.h>
#include <asm/pcr.h>
#include <linux/notifier.h>
#include <linux/rcupdate.h>
#include <linux/kdebug.h>
#include <asm/nmi.h>
static int nmi_enabled;
/* In order to commonize as much of the implementation as
* possible, we use PICH as our counter. Mostly this is
* to accomodate Niagara-1 which can only count insn cycles
* in PICH.
*/
static u64 picl_value(void)
static int profile_timer_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
u32 delta = local_cpu_data().clock_tick / HZ;
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
return ((u64)((0 - delta) & 0xffffffff)) << 32;
}
#define PCR_SUN4U_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE)
#define PCR_N2_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE | \
PCR_N2_TOE_OV1 | \
(2 << PCR_N2_SL1_SHIFT) | \
(0xff << PCR_N2_MASK1_SHIFT))
static u64 pcr_enable;
static void nmi_handler(struct pt_regs *regs)
{
pcr_ops->write(PCR_PIC_PRIV);
if (nmi_enabled) {
oprofile_add_sample(regs, 0);
write_pic(picl_value());
pcr_ops->write(pcr_enable);
}
}
/* We count "clock cycle" events in the lower 32-bit PIC.
* Then configure it such that it overflows every HZ, and thus
* generates a level 15 interrupt at that frequency.
*/
static void cpu_nmi_start(void *_unused)
{
pcr_ops->write(PCR_PIC_PRIV);
write_pic(picl_value());
pcr_ops->write(pcr_enable);
}
static void cpu_nmi_stop(void *_unused)
{
pcr_ops->write(PCR_PIC_PRIV);
}
static int nmi_start(void)
{
int err = register_perfctr_intr(nmi_handler);
if (!err) {
nmi_enabled = 1;
wmb();
err = on_each_cpu(cpu_nmi_start, NULL, 1);
if (err) {
nmi_enabled = 0;
wmb();
on_each_cpu(cpu_nmi_stop, NULL, 1);
release_perfctr_intr(nmi_handler);
}
}
return err;
}
static void nmi_stop(void)
{
nmi_enabled = 0;
wmb();
on_each_cpu(cpu_nmi_stop, NULL, 1);
release_perfctr_intr(nmi_handler);
synchronize_sched();
}
static int oprofile_nmi_init(struct oprofile_operations *ops)
{
switch (tlb_type) {
case hypervisor:
pcr_enable = PCR_N2_ENABLE;
switch (val) {
case DIE_NMI:
oprofile_add_sample(args->regs, 0);
ret = NOTIFY_STOP;
break;
case cheetah:
case cheetah_plus:
pcr_enable = PCR_SUN4U_ENABLE;
break;
default:
return -ENODEV;
break;
}
return ret;
}
ops->create_files = NULL;
ops->setup = NULL;
ops->shutdown = NULL;
ops->start = nmi_start;
ops->stop = nmi_stop;
static struct notifier_block profile_timer_exceptions_nb = {
.notifier_call = profile_timer_exceptions_notify,
};
static int timer_start(void)
{
if (register_die_notifier(&profile_timer_exceptions_nb))
return 1;
nmi_adjust_hz(HZ);
return 0;
}
static void timer_stop(void)
{
nmi_adjust_hz(1);
unregister_die_notifier(&profile_timer_exceptions_nb);
synchronize_sched(); /* Allow already-started NMIs to complete. */
}
static int op_nmi_timer_init(struct oprofile_operations *ops)
{
if (!nmi_usable)
return -ENODEV;
ops->start = timer_start;
ops->stop = timer_stop;
ops->cpu_type = "timer";
printk(KERN_INFO "oprofile: Using perfctr based NMI timer interrupt.\n");
printk(KERN_INFO "oprofile: Using perfctr NMI timer interrupt.\n");
return 0;
}
#endif
@ -133,7 +73,7 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
int ret = -ENODEV;
#ifdef CONFIG_SPARC64
ret = oprofile_nmi_init(ops);
ret = op_nmi_timer_init(ops);
if (!ret)
return ret;
#endif