diff options
Diffstat (limited to 'arch/arm/kernel/smp.c')
-rw-r--r-- | arch/arm/kernel/smp.c | 81 |
1 files changed, 71 insertions, 10 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index d88ff0230e82..a63326923e84 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -53,6 +53,7 @@ enum ipi_msg_type { IPI_CALL_FUNC, IPI_CALL_FUNC_SINGLE, IPI_CPU_STOP, + IPI_CPU_BACKTRACE, }; int __cpuinit __cpu_up(unsigned int cpu) @@ -301,17 +302,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) */ platform_secondary_init(cpu); - /* - * Enable local interrupts. - */ notify_cpu_starting(cpu); - local_irq_enable(); - local_fiq_enable(); - - /* - * Setup the percpu timer for this CPU. - */ - percpu_timer_setup(); calibrate_delay(); @@ -323,10 +314,23 @@ asmlinkage void __cpuinit secondary_start_kernel(void) * before we continue. */ set_cpu_online(cpu, true); + + /* + * Setup the percpu timer for this CPU. + */ + percpu_timer_setup(); + while (!cpu_active(cpu)) cpu_relax(); /* + * cpu_active bit is set, so it's safe to enable interrupts + * now. + */ + local_irq_enable(); + local_fiq_enable(); + + /* * OK, it's off to the idle thread for us */ cpu_idle(); @@ -412,6 +416,7 @@ static const char *ipi_types[NR_IPI] = { S(IPI_CALL_FUNC, "Function call interrupts"), S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"), S(IPI_CPU_STOP, "CPU stop interrupts"), + S(IPI_CPU_BACKTRACE, "CPU backtrace"), }; void show_ipi_list(struct seq_file *p, int prec) @@ -562,6 +567,58 @@ static void ipi_cpu_stop(unsigned int cpu) cpu_relax(); } +static cpumask_t backtrace_mask; +static DEFINE_RAW_SPINLOCK(backtrace_lock); + +/* "in progress" flag of arch_trigger_all_cpu_backtrace */ +static unsigned long backtrace_flag; + +void smp_send_all_cpu_backtrace(void) +{ + unsigned int this_cpu = smp_processor_id(); + int i; + + if (test_and_set_bit(0, &backtrace_flag)) + /* + * If there is already a trigger_all_cpu_backtrace() in progress + * (backtrace_flag == 1), don't output double cpu dump infos. + */ + return; + + cpumask_copy(&backtrace_mask, cpu_online_mask); + cpu_clear(this_cpu, backtrace_mask); + + pr_info("Backtrace for cpu %d (current):\n", this_cpu); + dump_stack(); + + pr_info("\nsending IPI to all other CPUs:\n"); + smp_cross_call(&backtrace_mask, IPI_CPU_BACKTRACE); + + /* Wait for up to 10 seconds for all other CPUs to do the backtrace */ + for (i = 0; i < 10 * 1000; i++) { + if (cpumask_empty(&backtrace_mask)) + break; + mdelay(1); + } + + clear_bit(0, &backtrace_flag); + smp_mb__after_clear_bit(); +} + +/* + * ipi_cpu_backtrace - handle IPI from smp_send_all_cpu_backtrace() + */ +static void ipi_cpu_backtrace(unsigned int cpu, struct pt_regs *regs) +{ + if (cpu_isset(cpu, backtrace_mask)) { + raw_spin_lock(&backtrace_lock); + pr_warning("IPI backtrace for cpu %d\n", cpu); + show_regs(regs); + raw_spin_unlock(&backtrace_lock); + cpu_clear(cpu, backtrace_mask); + } +} + /* * Main handler for inter-processor interrupts */ @@ -594,6 +651,10 @@ asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs) ipi_cpu_stop(cpu); break; + case IPI_CPU_BACKTRACE: + ipi_cpu_backtrace(cpu, regs); + break; + default: printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr); |