1 #include <linux/kernel.h> 2 #include <linux/smp.h> 3 #include <linux/reboot.h> 4 #include <linux/kexec.h> 5 #include <linux/bootmem.h> 6 #include <linux/crash_dump.h> 7 #include <linux/delay.h> 8 #include <linux/irq.h> 9 #include <linux/types.h> 10 #include <linux/sched.h> 11 12 /* This keeps a track of which one is crashing cpu. */ 13 static int crashing_cpu = -1; 14 static cpumask_t cpus_in_crash = CPU_MASK_NONE; 15 16 #ifdef CONFIG_SMP 17 static void crash_shutdown_secondary(void *passed_regs) 18 { 19 struct pt_regs *regs = passed_regs; 20 int cpu = smp_processor_id(); 21 22 /* 23 * If we are passed registers, use those. Otherwise get the 24 * regs from the last interrupt, which should be correct, as 25 * we are in an interrupt. But if the regs are not there, 26 * pull them from the top of the stack. They are probably 27 * wrong, but we need something to keep from crashing again. 28 */ 29 if (!regs) 30 regs = get_irq_regs(); 31 if (!regs) 32 regs = task_pt_regs(current); 33 34 if (!cpu_online(cpu)) 35 return; 36 37 local_irq_disable(); 38 if (!cpumask_test_cpu(cpu, &cpus_in_crash)) 39 crash_save_cpu(regs, cpu); 40 cpumask_set_cpu(cpu, &cpus_in_crash); 41 42 while (!atomic_read(&kexec_ready_to_reboot)) 43 cpu_relax(); 44 relocated_kexec_smp_wait(NULL); 45 /* NOTREACHED */ 46 } 47 48 static void crash_kexec_prepare_cpus(void) 49 { 50 unsigned int msecs; 51 52 unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ 53 54 dump_send_ipi(crash_shutdown_secondary); 55 smp_wmb(); 56 57 /* 58 * The crash CPU sends an IPI and wait for other CPUs to 59 * respond. Delay of at least 10 seconds. 60 */ 61 pr_emerg("Sending IPI to other cpus...\n"); 62 msecs = 10000; 63 while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) { 64 cpu_relax(); 65 mdelay(1); 66 } 67 } 68 69 #else /* !defined(CONFIG_SMP) */ 70 static void crash_kexec_prepare_cpus(void) {} 71 #endif /* !defined(CONFIG_SMP) */ 72 73 void default_machine_crash_shutdown(struct pt_regs *regs) 74 { 75 local_irq_disable(); 76 crashing_cpu = smp_processor_id(); 77 crash_save_cpu(regs, crashing_cpu); 78 crash_kexec_prepare_cpus(); 79 cpumask_set_cpu(crashing_cpu, &cpus_in_crash); 80 } 81