diff options
Diffstat (limited to 'arch/sparc/kernel/nmi.c')
| -rw-r--r-- | arch/sparc/kernel/nmi.c | 74 |
1 files changed, 54 insertions, 20 deletions
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c index 2c0cc72d295..378eb53e077 100644 --- a/arch/sparc/kernel/nmi.c +++ b/arch/sparc/kernel/nmi.c @@ -19,6 +19,7 @@ #include <linux/delay.h> #include <linux/smp.h> +#include <asm/perf_counter.h> #include <asm/ptrace.h> #include <asm/local.h> #include <asm/pcr.h> @@ -31,13 +32,19 @@ * 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); @@ -45,7 +52,7 @@ 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) { @@ -78,6 +85,7 @@ static void die_nmi(const char *str, struct pt_regs *regs, int do_panic) if (do_panic || panic_on_oops) panic("Non maskable interrupt"); + nmi_exit(); local_irq_enable(); do_exit(SIGBUS); } @@ -92,6 +100,8 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs) local_cpu_data().__nmi_count++; + nmi_enter(); + if (notify_die(DIE_NMI, "nmi", regs, 0, pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP) touched = 1; @@ -103,17 +113,19 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs) } 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) + if (local_read(&__get_cpu_var(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); } - if (nmi_usable) { + if (__get_cpu_var(wd_enabled)) { write_pic(picl_value(nmi_hz)); pcr_ops->write(pcr_enable); } + + nmi_exit(); } static inline unsigned int get_nmi_count(int cpu) @@ -121,8 +133,6 @@ 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(); @@ -143,12 +153,15 @@ 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); + __get_cpu_var(wd_enabled) = 0; + atomic_dec(&nmi_active); } static int __init check_nmi_watchdog(void) @@ -156,6 +169,9 @@ 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; @@ -172,12 +188,15 @@ 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; } @@ -188,12 +207,26 @@ 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) { + __get_cpu_var(wd_enabled) = 1; + atomic_inc(&nmi_active); + + pcr_ops->write(PCR_PIC_PRIV); + write_pic(picl_value(nmi_hz)); + + pcr_ops->write(pcr_enable); +} + +static void nmi_adjust_hz_one(void *unused) +{ + if (!__get_cpu_var(wd_enabled)) + return; + pcr_ops->write(PCR_PIC_PRIV); write_pic(picl_value(nmi_hz)); @@ -203,13 +236,13 @@ static void start_watchdog(void *unused) 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_watchdog, NULL, 1); + on_each_cpu(stop_nmi_watchdog, NULL, 1); return 0; } @@ -221,18 +254,19 @@ int __init nmi_init(void) { int err; - nmi_usable = 1; - - on_each_cpu(start_watchdog, NULL, 1); + on_each_cpu(start_nmi_watchdog, NULL, 1); err = check_nmi_watchdog(); if (!err) { err = register_reboot_notifier(&nmi_reboot_notifier); if (err) { - nmi_usable = 0; - on_each_cpu(stop_watchdog, NULL, 1); + on_each_cpu(stop_nmi_watchdog, NULL, 1); + atomic_set(&nmi_active, -1); } } + if (!err) + init_hw_perf_counters(); + return err; } |