@@ -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;
@@ -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
@@ -14,6 +14,8 @@ enum die_val {
DIE_TRAP,
DIE_TRAP_TL1,
DIE_CALL,
+ DIE_NMI,
+ DIE_NMIWATCHDOG,
};
#endif
new file mode 100644
@@ -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 */
@@ -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 */
@@ -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
@@ -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)
{
new file mode 100644
@@ -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);
@@ -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();
@@ -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)
-{
- 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
Signed-off-by: David S. Miller <davem@davemloft.net> --- 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