From e5553a6d04421eec326a629571d696e8e745a0e4 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 29 Jan 2009 21:22:47 -0800 Subject: sparc64: Implement NMI watchdog on capable cpus. Signed-off-by: David S. Miller --- arch/sparc/kernel/Makefile | 1 + arch/sparc/kernel/irq_64.c | 68 +------------- arch/sparc/kernel/nmi.c | 224 +++++++++++++++++++++++++++++++++++++++++++++ arch/sparc/kernel/pcr.c | 17 +++- 4 files changed, 245 insertions(+), 65 deletions(-) create mode 100644 arch/sparc/kernel/nmi.c (limited to 'arch/sparc/kernel') diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile index cb182d9c2f2..54742e58831 100644 --- a/arch/sparc/kernel/Makefile +++ b/arch/sparc/kernel/Makefile @@ -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 diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index cab8e028687..e289376198e 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -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) { diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c new file mode 100644 index 00000000000..ffc69009334 --- /dev/null +++ b/arch/sparc/kernel/nmi.c @@ -0,0 +1,224 @@ +/* Pseudo NMI support on sparc64 systems. + * + * Copyright (C) 2009 David S. Miller + * + * The NMI watchdog support and infrastructure is based almost + * entirely upon the x86 NMI support code. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* 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); diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c index c4f24703b16..92e0dda141a 100644 --- a/arch/sparc/kernel/pcr.c +++ b/arch/sparc/kernel/pcr.c @@ -9,12 +9,22 @@ #include #include +#include /* 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(); -- cgit v1.2.3