diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2010-11-22 13:32:15 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2010-11-22 13:32:15 +1100 |
commit | a6bb57a60537f7d12649160cf1d6d6945664b01a (patch) | |
tree | a45f03463da1e87f3bda24d163407468b28a208b | |
parent | 4d165a921c77f8335d3bc4bfd33cca5ec41f83f6 (diff) |
Revert "x86, nmi_watchdog: Remove the old nmi_watchdog"
This reverts commit 5f2b0ba4d94b3ac23cbc4b7f675d98eb677a760a.
Conflicts:
arch/x86/kernel/apic/hw_nmi.c
-rw-r--r-- | arch/x86/include/asm/nmi.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/apic/Makefile | 5 | ||||
-rw-r--r-- | arch/x86/kernel/apic/hw_nmi.c | 6 | ||||
-rw-r--r-- | arch/x86/kernel/apic/nmi.c | 567 | ||||
-rw-r--r-- | arch/x86/kernel/traps.c | 9 | ||||
-rw-r--r-- | include/linux/nmi.h | 6 | ||||
-rw-r--r-- | kernel/sysctl.c | 16 |
7 files changed, 608 insertions, 5 deletions
diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h index 33292ec848ca..932f0f86b4b7 100644 --- a/arch/x86/include/asm/nmi.h +++ b/arch/x86/include/asm/nmi.h @@ -17,6 +17,9 @@ int do_nmi_callback(struct pt_regs *regs, int cpu); extern void die_nmi(char *str, struct pt_regs *regs, int do_panic); extern int check_nmi_watchdog(void); +#if !defined(CONFIG_LOCKUP_DETECTOR) +extern int nmi_watchdog_enabled; +#endif extern int avail_to_resrv_perfctr_nmi_bit(unsigned int); extern int reserve_perfctr_nmi(unsigned int); extern void release_perfctr_nmi(unsigned int); @@ -27,6 +30,7 @@ extern void setup_apic_nmi_watchdog(void *); extern void stop_apic_nmi_watchdog(void *); extern void disable_timer_nmi_watchdog(void); extern void enable_timer_nmi_watchdog(void); +extern int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason); extern void cpu_nmi_set_wd_enabled(void); extern atomic_t nmi_active; diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile index 3966b564ea47..910f20b457c4 100644 --- a/arch/x86/kernel/apic/Makefile +++ b/arch/x86/kernel/apic/Makefile @@ -3,7 +3,10 @@ # obj-$(CONFIG_X86_LOCAL_APIC) += apic.o apic_noop.o probe_$(BITS).o ipi.o -obj-y += hw_nmi.o +ifneq ($(CONFIG_HARDLOCKUP_DETECTOR),y) +obj-$(CONFIG_X86_LOCAL_APIC) += nmi.o +endif +obj-$(CONFIG_HARDLOCKUP_DETECTOR) += hw_nmi.o obj-$(CONFIG_X86_IO_APIC) += io_apic.o obj-$(CONFIG_SMP) += ipi.o diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index f4a37eb89b49..62f6e1e55b90 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -17,18 +17,16 @@ #include <linux/nmi.h> #include <linux/module.h> -#ifdef CONFIG_HARDLOCKUP_DETECTOR u64 hw_nmi_get_sample_period(void) { return (u64)(cpu_khz) * 1000 * 60; } -#endif +#ifdef ARCH_HAS_NMI_WATCHDOG /* For reliability, we're prepared to waste bits here. */ static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly; -#ifdef arch_trigger_all_cpu_backtrace void arch_trigger_all_cpu_backtrace(void) { int i; @@ -98,6 +96,8 @@ early_initcall(register_trigger_all_cpu_backtrace); #if defined(CONFIG_X86_LOCAL_APIC) unsigned int nmi_watchdog = NMI_NONE; EXPORT_SYMBOL(nmi_watchdog); +void acpi_nmi_enable(void) { return; } +void acpi_nmi_disable(void) { return; } #endif atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ EXPORT_SYMBOL(nmi_active); diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c new file mode 100644 index 000000000000..c90041ccb742 --- /dev/null +++ b/arch/x86/kernel/apic/nmi.c @@ -0,0 +1,567 @@ +/* + * NMI watchdog support on APIC systems + * + * Started by Ingo Molnar <mingo@redhat.com> + * + * Fixes: + * Mikael Pettersson : AMD K7 support for local APIC NMI watchdog. + * Mikael Pettersson : Power Management for local APIC NMI watchdog. + * Mikael Pettersson : Pentium 4 support for local APIC NMI watchdog. + * Pavel Machek and + * Mikael Pettersson : PM converted to driver model. Disable/enable API. + */ + +#include <asm/apic.h> + +#include <linux/nmi.h> +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/sysdev.h> +#include <linux/sysctl.h> +#include <linux/percpu.h> +#include <linux/kprobes.h> +#include <linux/cpumask.h> +#include <linux/kernel_stat.h> +#include <linux/kdebug.h> +#include <linux/smp.h> + +#include <asm/i8259.h> +#include <asm/io_apic.h> +#include <asm/proto.h> +#include <asm/timer.h> + +#include <asm/mce.h> + +#include <asm/mach_traps.h> + +int unknown_nmi_panic; +int nmi_watchdog_enabled; + +/* For reliability, we're prepared to waste bits here. */ +static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly; + +/* nmi_active: + * >0: the lapic NMI watchdog is active, but can be disabled + * <0: the lapic NMI watchdog has not been set up, and cannot + * be enabled + * 0: the lapic NMI watchdog is disabled, but can be enabled + */ +atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ +EXPORT_SYMBOL(nmi_active); + +unsigned int nmi_watchdog = NMI_NONE; +EXPORT_SYMBOL(nmi_watchdog); + +static int panic_on_timeout; + +static unsigned int nmi_hz = HZ; +static DEFINE_PER_CPU(short, wd_enabled); +static int endflag __initdata; + +static inline unsigned int get_nmi_count(int cpu) +{ + return per_cpu(irq_stat, cpu).__nmi_count; +} + +static inline int mce_in_progress(void) +{ +#if defined(CONFIG_X86_MCE) + return atomic_read(&mce_entry) > 0; +#endif + return 0; +} + +/* + * Take the local apic timer and PIT/HPET into account. We don't + * know which one is active, when we have highres/dyntick on + */ +static inline unsigned int get_timer_irqs(int cpu) +{ + return per_cpu(irq_stat, cpu).apic_timer_irqs + + per_cpu(irq_stat, cpu).irq0_irqs; +} + +#ifdef CONFIG_SMP +/* + * The performance counters used by NMI_LOCAL_APIC don't trigger when + * the CPU is idle. To make sure the NMI watchdog really ticks on all + * CPUs during the test make them busy. + */ +static __init void nmi_cpu_busy(void *data) +{ + local_irq_enable_in_hardirq(); + /* + * Intentionally don't use cpu_relax here. This is + * to make sure that the performance counter really ticks, + * even if there is a simulator or similar that catches the + * pause instruction. On a real HT machine this is fine because + * all other CPUs are busy with "useless" delay loops and don't + * care if they get somewhat less cycles. + */ + while (endflag == 0) + mb(); +} +#endif + +static void report_broken_nmi(int cpu, unsigned 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); +} + +static void __acpi_nmi_disable(void *__unused) +{ + apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED); +} + +int __init check_nmi_watchdog(void) +{ + unsigned int *prev_nmi_count; + int cpu; + + if (!nmi_watchdog_active() || !atomic_read(&nmi_active)) + return 0; + + prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); + if (!prev_nmi_count) + goto error; + + printk(KERN_INFO "Testing NMI watchdog ... "); + +#ifdef CONFIG_SMP + if (nmi_watchdog == NMI_LOCAL_APIC) + smp_call_function(nmi_cpu_busy, (void *)&endflag, 0); +#endif + + 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); + goto error; + } + printk("OK.\n"); + + /* + * now that we know it works we can reduce NMI frequency to + * something more reasonable; makes a difference in some configs + */ + if (nmi_watchdog == NMI_LOCAL_APIC) + nmi_hz = lapic_adjust_nmi_hz(1); + + kfree(prev_nmi_count); + return 0; +error: + if (nmi_watchdog == NMI_IO_APIC) { + if (!timer_through_8259) + legacy_pic->mask(0); + on_each_cpu(__acpi_nmi_disable, NULL, 1); + } + +#ifdef CONFIG_X86_32 + timer_ack = 0; +#endif + return -1; +} + +static int __init setup_nmi_watchdog(char *str) +{ + unsigned int nmi; + + if (!strncmp(str, "panic", 5)) { + panic_on_timeout = 1; + str = strchr(str, ','); + if (!str) + return 1; + ++str; + } + + if (!strncmp(str, "lapic", 5)) + nmi_watchdog = NMI_LOCAL_APIC; + else if (!strncmp(str, "ioapic", 6)) + nmi_watchdog = NMI_IO_APIC; + else { + get_option(&str, &nmi); + if (nmi >= NMI_INVALID) + return 0; + nmi_watchdog = nmi; + } + + return 1; +} +__setup("nmi_watchdog=", setup_nmi_watchdog); + +/* + * Suspend/resume support + */ +#ifdef CONFIG_PM + +static int nmi_pm_active; /* nmi_active before suspend */ + +static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state) +{ + /* only CPU0 goes here, other CPUs should be offline */ + nmi_pm_active = atomic_read(&nmi_active); + stop_apic_nmi_watchdog(NULL); + BUG_ON(atomic_read(&nmi_active) != 0); + return 0; +} + +static int lapic_nmi_resume(struct sys_device *dev) +{ + /* only CPU0 goes here, other CPUs should be offline */ + if (nmi_pm_active > 0) { + setup_apic_nmi_watchdog(NULL); + touch_nmi_watchdog(); + } + return 0; +} + +static struct sysdev_class nmi_sysclass = { + .name = "lapic_nmi", + .resume = lapic_nmi_resume, + .suspend = lapic_nmi_suspend, +}; + +static struct sys_device device_lapic_nmi = { + .id = 0, + .cls = &nmi_sysclass, +}; + +static int __init init_lapic_nmi_sysfs(void) +{ + int error; + + /* + * should really be a BUG_ON but b/c this is an + * init call, it just doesn't work. -dcz + */ + if (nmi_watchdog != NMI_LOCAL_APIC) + return 0; + + if (atomic_read(&nmi_active) < 0) + return 0; + + error = sysdev_class_register(&nmi_sysclass); + if (!error) + error = sysdev_register(&device_lapic_nmi); + return error; +} + +/* must come after the local APIC's device_initcall() */ +late_initcall(init_lapic_nmi_sysfs); + +#endif /* CONFIG_PM */ + +static void __acpi_nmi_enable(void *__unused) +{ + apic_write(APIC_LVT0, APIC_DM_NMI); +} + +/* + * Enable timer based NMIs on all CPUs: + */ +void acpi_nmi_enable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_enable, NULL, 1); +} + +/* + * Disable timer based NMIs on all CPUs: + */ +void acpi_nmi_disable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_disable, NULL, 1); +} + +/* + * This function is called as soon the LAPIC NMI watchdog driver has everything + * in place and it's ready to check if the NMIs belong to the NMI watchdog + */ +void cpu_nmi_set_wd_enabled(void) +{ + __get_cpu_var(wd_enabled) = 1; +} + +void setup_apic_nmi_watchdog(void *unused) +{ + if (__get_cpu_var(wd_enabled)) + return; + + /* cheap hack to support suspend/resume */ + /* if cpu0 is not active neither should the other cpus */ + if (smp_processor_id() != 0 && atomic_read(&nmi_active) <= 0) + return; + + switch (nmi_watchdog) { + case NMI_LOCAL_APIC: + if (lapic_watchdog_init(nmi_hz) < 0) { + __get_cpu_var(wd_enabled) = 0; + return; + } + /* FALL THROUGH */ + case NMI_IO_APIC: + __get_cpu_var(wd_enabled) = 1; + atomic_inc(&nmi_active); + } +} + +void stop_apic_nmi_watchdog(void *unused) +{ + /* only support LOCAL and IO APICs for now */ + if (!nmi_watchdog_active()) + return; + if (__get_cpu_var(wd_enabled) == 0) + return; + if (nmi_watchdog == NMI_LOCAL_APIC) + lapic_watchdog_stop(); + else + __acpi_nmi_disable(NULL); + __get_cpu_var(wd_enabled) = 0; + atomic_dec(&nmi_active); +} + +/* + * the best way to detect whether a CPU has a 'hard lockup' problem + * is to check it's local APIC timer IRQ counts. If they are not + * changing then that CPU has some problem. + * + * as these watchdog NMI IRQs are generated on every CPU, we only + * have to check the current processor. + * + * since NMIs don't listen to _any_ locks, we have to be extremely + * careful not to rely on unsafe variables. The printk might lock + * up though, so we have to break up any console locks first ... + * [when there will be more tty-related locks, break them up here too!] + */ + +static DEFINE_PER_CPU(unsigned, last_irq_sum); +static DEFINE_PER_CPU(long, alert_counter); +static DEFINE_PER_CPU(int, nmi_touch); + +void touch_nmi_watchdog(void) +{ + if (nmi_watchdog_active()) { + unsigned cpu; + + /* + * Tell other CPUs to reset their alert counters. We cannot + * do it ourselves because the alert count increase is not + * atomic. + */ + for_each_present_cpu(cpu) { + if (per_cpu(nmi_touch, cpu) != 1) + per_cpu(nmi_touch, cpu) = 1; + } + } + + /* + * Tickle the softlockup detector too: + */ + touch_softlockup_watchdog(); +} +EXPORT_SYMBOL(touch_nmi_watchdog); + +notrace __kprobes int +nmi_watchdog_tick(struct pt_regs *regs, unsigned reason) +{ + /* + * Since current_thread_info()-> is always on the stack, and we + * always switch the stack NMI-atomically, it's safe to use + * smp_processor_id(). + */ + unsigned int sum; + int touched = 0; + int cpu = smp_processor_id(); + int rc = 0; + + sum = get_timer_irqs(cpu); + + if (__get_cpu_var(nmi_touch)) { + __get_cpu_var(nmi_touch) = 0; + touched = 1; + } + + /* We can be called before check_nmi_watchdog, hence NULL check. */ + if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { + static DEFINE_RAW_SPINLOCK(lock); /* Serialise the printks */ + + raw_spin_lock(&lock); + printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu); + show_regs(regs); + dump_stack(); + raw_spin_unlock(&lock); + cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); + + rc = 1; + } + + /* Could check oops_in_progress here too, but it's safer not to */ + if (mce_in_progress()) + touched = 1; + + /* if the none of the timers isn't firing, this cpu isn't doing much */ + if (!touched && __get_cpu_var(last_irq_sum) == sum) { + /* + * Ayiee, looks like this CPU is stuck ... + * wait a few IRQs (5 seconds) before doing the oops ... + */ + __this_cpu_inc(alert_counter); + if (__this_cpu_read(alert_counter) == 5 * nmi_hz) + /* + * die_nmi will return ONLY if NOTIFY_STOP happens.. + */ + 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); + } + + /* see if the nmi watchdog went off */ + if (!__get_cpu_var(wd_enabled)) + return rc; + switch (nmi_watchdog) { + case NMI_LOCAL_APIC: + rc |= lapic_wd_event(nmi_hz); + break; + case NMI_IO_APIC: + /* + * don't know how to accurately check for this. + * just assume it was a watchdog timer interrupt + * This matches the old behaviour. + */ + rc = 1; + break; + } + return rc; +} + +#ifdef CONFIG_SYSCTL + +static void enable_ioapic_nmi_watchdog_single(void *unused) +{ + __get_cpu_var(wd_enabled) = 1; + atomic_inc(&nmi_active); + __acpi_nmi_enable(NULL); +} + +static void enable_ioapic_nmi_watchdog(void) +{ + on_each_cpu(enable_ioapic_nmi_watchdog_single, NULL, 1); + touch_nmi_watchdog(); +} + +static void disable_ioapic_nmi_watchdog(void) +{ + on_each_cpu(stop_apic_nmi_watchdog, NULL, 1); +} + +static int __init setup_unknown_nmi_panic(char *str) +{ + unknown_nmi_panic = 1; + return 1; +} +__setup("unknown_nmi_panic", setup_unknown_nmi_panic); + +static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) +{ + unsigned char reason = get_nmi_reason(); + char buf[64]; + + sprintf(buf, "NMI received for unknown reason %02x\n", reason); + die_nmi(buf, regs, 1); /* Always panic here */ + return 0; +} + +/* + * proc handler for /proc/sys/kernel/nmi + */ +int proc_nmi_enabled(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int old_state; + + nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0; + old_state = nmi_watchdog_enabled; + proc_dointvec(table, write, buffer, length, ppos); + if (!!old_state == !!nmi_watchdog_enabled) + return 0; + + if (atomic_read(&nmi_active) < 0 || !nmi_watchdog_active()) { + printk(KERN_WARNING + "NMI watchdog is permanently disabled\n"); + return -EIO; + } + + if (nmi_watchdog == NMI_LOCAL_APIC) { + if (nmi_watchdog_enabled) + enable_lapic_nmi_watchdog(); + else + disable_lapic_nmi_watchdog(); + } else if (nmi_watchdog == NMI_IO_APIC) { + if (nmi_watchdog_enabled) + enable_ioapic_nmi_watchdog(); + else + disable_ioapic_nmi_watchdog(); + } else { + printk(KERN_WARNING + "NMI watchdog doesn't know what hardware to touch\n"); + return -EIO; + } + return 0; +} + +#endif /* CONFIG_SYSCTL */ + +int do_nmi_callback(struct pt_regs *regs, int cpu) +{ +#ifdef CONFIG_SYSCTL + if (unknown_nmi_panic) + return unknown_nmi_panic_callback(regs, cpu); +#endif + return 0; +} + +void arch_trigger_all_cpu_backtrace(void) +{ + int i; + + cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask); + + printk(KERN_INFO "sending NMI to all CPUs:\n"); + apic->send_IPI_all(NMI_VECTOR); + + /* Wait for up to 10 seconds for all CPUs to do the backtrace */ + for (i = 0; i < 10 * 1000; i++) { + if (cpumask_empty(to_cpumask(backtrace_mask))) + break; + mdelay(1); + } +} diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index db30d9cb9dd6..cb838ca42c96 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -398,6 +398,15 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs) == NOTIFY_STOP) return; +#ifndef CONFIG_LOCKUP_DETECTOR + /* + * Ok, so this is none of the documented NMI sources, + * so it must be the NMI watchdog. + */ + if (nmi_watchdog_tick(regs, reason)) + return; + if (!do_nmi_callback(regs, cpu)) +#endif /* !CONFIG_LOCKUP_DETECTOR */ unknown_nmi_error(reason, regs); #else unknown_nmi_error(reason, regs); diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 0cb3e5c246d0..06aab5eee134 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -16,7 +16,10 @@ */ #ifdef ARCH_HAS_NMI_WATCHDOG #include <asm/nmi.h> -#endif +extern void touch_nmi_watchdog(void); +extern void acpi_nmi_disable(void); +extern void acpi_nmi_enable(void); +#else #ifndef CONFIG_HARDLOCKUP_DETECTOR static inline void touch_nmi_watchdog(void) { @@ -27,6 +30,7 @@ extern void touch_nmi_watchdog(void); #endif static inline void acpi_nmi_disable(void) { } static inline void acpi_nmi_enable(void) { } +#endif /* * Create trigger_all_cpu_backtrace() out of the arch-provided diff --git a/kernel/sysctl.c b/kernel/sysctl.c index d91b07d022f7..a00fdefd24ce 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -734,6 +734,22 @@ static struct ctl_table kern_table[] = { .extra2 = &one, }, #endif +#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR) + { + .procname = "unknown_nmi_panic", + .data = &unknown_nmi_panic, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "nmi_watchdog", + .data = &nmi_watchdog_enabled, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = proc_nmi_enabled, + }, +#endif #if defined(CONFIG_X86) { .procname = "panic_on_unrecovered_nmi", |