From e5553a6d04421eec326a629571d696e8e745a0e4 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 29 Jan 2009 21:22:47 -0800 Subject: [PATCH] sparc64: Implement NMI watchdog on capable cpus. Signed-off-by: David S. Miller --- arch/sparc/include/asm/cpudata_64.h | 2 +- arch/sparc/include/asm/irq_64.h | 4 +- arch/sparc/include/asm/kdebug_64.h | 2 + arch/sparc/include/asm/nmi.h | 10 ++ arch/sparc/include/asm/pcr.h | 16 ++ arch/sparc/kernel/Makefile | 1 + arch/sparc/kernel/irq_64.c | 68 +-------- arch/sparc/kernel/nmi.c | 224 ++++++++++++++++++++++++++++ arch/sparc/kernel/pcr.c | 17 ++- arch/sparc/oprofile/init.c | 128 +++++----------- 10 files changed, 309 insertions(+), 163 deletions(-) create mode 100644 arch/sparc/include/asm/nmi.h create mode 100644 arch/sparc/kernel/nmi.c diff --git a/arch/sparc/include/asm/cpudata_64.h b/arch/sparc/include/asm/cpudata_64.h index 7da7c13d23c4..a11b89ee9ef8 100644 --- a/arch/sparc/include/asm/cpudata_64.h +++ b/arch/sparc/include/asm/cpudata_64.h @@ -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; diff --git a/arch/sparc/include/asm/irq_64.h b/arch/sparc/include/asm/irq_64.h index d47d4a1955a9..1934f2cbf513 100644 --- a/arch/sparc/include/asm/irq_64.h +++ b/arch/sparc/include/asm/irq_64.h @@ -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 diff --git a/arch/sparc/include/asm/kdebug_64.h b/arch/sparc/include/asm/kdebug_64.h index f905b773235a..feb3578e12c4 100644 --- a/arch/sparc/include/asm/kdebug_64.h +++ b/arch/sparc/include/asm/kdebug_64.h @@ -14,6 +14,8 @@ enum die_val { DIE_TRAP, DIE_TRAP_TL1, DIE_CALL, + DIE_NMI, + DIE_NMIWATCHDOG, }; #endif diff --git a/arch/sparc/include/asm/nmi.h b/arch/sparc/include/asm/nmi.h new file mode 100644 index 000000000000..fbd546dd4feb --- /dev/null +++ b/arch/sparc/include/asm/nmi.h @@ -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 */ diff --git a/arch/sparc/include/asm/pcr.h b/arch/sparc/include/asm/pcr.h index 4249bb523ef1..a2f5c61f924e 100644 --- a/arch/sparc/include/asm/pcr.h +++ b/arch/sparc/include/asm/pcr.h @@ -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 */ diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile index cb182d9c2f2b..54742e58831c 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 cab8e0286871..e289376198eb 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 000000000000..ffc690093343 --- /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 c4f24703b165..92e0dda141a4 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(); diff --git a/arch/sparc/oprofile/init.c b/arch/sparc/oprofile/init.c index c8877a5202b0..d172f86439b1 100644 --- a/arch/sparc/oprofile/init.c +++ b/arch/sparc/oprofile/init.c @@ -13,117 +13,57 @@ #include #ifdef CONFIG_SPARC64 -#include -#include -#include -#include -#include +#include +#include +#include +#include -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) -{ - u32 delta = local_cpu_data().clock_tick / HZ; - - 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) +static int profile_timer_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) { - pcr_ops->write(PCR_PIC_PRIV); + struct die_args *args = (struct die_args *)data; + int ret = NOTIFY_DONE; - if (nmi_enabled) { - oprofile_add_sample(regs, 0); - - write_pic(picl_value()); - pcr_ops->write(pcr_enable); + switch (val) { + case DIE_NMI: + oprofile_add_sample(args->regs, 0); + ret = NOTIFY_STOP; + break; + default: + break; } + return ret; } -/* 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 struct notifier_block profile_timer_exceptions_nb = { + .notifier_call = profile_timer_exceptions_notify, +}; -static void cpu_nmi_stop(void *_unused) +static int timer_start(void) { - pcr_ops->write(PCR_PIC_PRIV); + if (register_die_notifier(&profile_timer_exceptions_nb)) + return 1; + nmi_adjust_hz(HZ); + return 0; } -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) +static void timer_stop(void) { - nmi_enabled = 0; - wmb(); - - on_each_cpu(cpu_nmi_stop, NULL, 1); - release_perfctr_intr(nmi_handler); - synchronize_sched(); + nmi_adjust_hz(1); + unregister_die_notifier(&profile_timer_exceptions_nb); + synchronize_sched(); /* Allow already-started NMIs to complete. */ } -static int oprofile_nmi_init(struct oprofile_operations *ops) +static int op_nmi_timer_init(struct oprofile_operations *ops) { - switch (tlb_type) { - case hypervisor: - pcr_enable = PCR_N2_ENABLE; - break; - - case cheetah: - case cheetah_plus: - pcr_enable = PCR_SUN4U_ENABLE; - break; - - default: + if (!nmi_usable) return -ENODEV; - } - ops->create_files = NULL; - ops->setup = NULL; - ops->shutdown = NULL; - ops->start = nmi_start; - ops->stop = nmi_stop; + 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 -- 2.20.1