diff options
Diffstat (limited to 'arch/arm64/kernel/smp.c')
| -rw-r--r-- | arch/arm64/kernel/smp.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 328b8ce4b007..9369eee1fa9f 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -68,6 +68,7 @@ enum ipi_msg_type { IPI_CPU_STOP, IPI_TIMER, IPI_IRQ_WORK, + IPI_CPU_BACKTRACE, }; /* @@ -485,6 +486,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = { S(IPI_CPU_STOP, "CPU stop interrupts"), S(IPI_TIMER, "Timer broadcast interrupts"), S(IPI_IRQ_WORK, "IRQ work interrupts"), + S(IPI_CPU_BACKTRACE, "backtrace interrupts"), }; static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) @@ -559,6 +561,66 @@ static void ipi_cpu_stop(unsigned int cpu) cpu_relax(); } +#ifdef CONFIG_USE_ICC_SYSREGS_FOR_IRQFLAGS + +/* For reliability, we're prepared to waste bits here. */ +static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly; + +void arch_trigger_all_cpu_backtrace(bool include_self) +{ + int i; + int this_cpu = get_cpu(); + + if (0 != printk_nmi_backtrace_prepare()) { + /* + * If there is already an nmi printk sequence in + * progress then just give up... + */ + put_cpu(); + return; + } + + cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask); + if (!include_self) + cpumask_clear_cpu(this_cpu, to_cpumask(backtrace_mask)); + + if (!cpumask_empty(to_cpumask(backtrace_mask))) { + pr_info("Sending NMI to %s CPUs:\n", + (include_self ? "all" : "other")); + smp_cross_call(to_cpumask(backtrace_mask), IPI_CPU_BACKTRACE); + } + + /* Wait for up to 10 seconds for all CPUs to do the backtrace */ + for (i = 0; i < 3 * 1000; i++) { + if (cpumask_empty(to_cpumask(backtrace_mask))) + break; + mdelay(1); + touch_softlockup_watchdog(); + } + + printk_nmi_backtrace_complete(); + put_cpu(); +} + +void ipi_cpu_backtrace(struct pt_regs *regs) +{ + int cpu = smp_processor_id(); + + BUILD_BUG_ON(SMP_IPI_NMI_MASK != BIT(IPI_CPU_BACKTRACE)); + + if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { + printk_nmi_backtrace_this_cpu_begin(); + pr_warn("NMI backtrace for cpu %d\n", cpu); + show_regs(regs); + show_stack(NULL, NULL); + printk_nmi_backtrace_this_cpu_end(); + + cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); + } +} + +#endif /* CONFIG_USE_ICC_SYSREGS_FOR_IRQFLAGS */ + /* * Main handler for inter-processor interrupts */ @@ -605,6 +667,14 @@ void handle_IPI(int ipinr, struct pt_regs *regs) break; #endif +#ifdef CONFIG_USE_ICC_SYSREGS_FOR_IRQFLAGS + case IPI_CPU_BACKTRACE: + nmi_enter(); + ipi_cpu_backtrace(regs); + nmi_exit(); + break; +#endif + default: pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr); break; |