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/init.h> 9 #include <linux/irq.h> 10 #include <linux/types.h> 11 #include <linux/sched.h> 12 13 /* This keeps a track of which one is crashing cpu. */ 14 static int crashing_cpu = -1; 15 static cpumask_t cpus_in_crash = CPU_MASK_NONE; 16 17 #ifdef CONFIG_SMP 18 static void crash_shutdown_secondary(void *ignore) 19 { 20 struct pt_regs *regs; 21 int cpu = smp_processor_id(); 22 23 regs = task_pt_regs(current); 24 25 if (!cpu_online(cpu)) 26 return; 27 28 local_irq_disable(); 29 if (!cpu_isset(cpu, cpus_in_crash)) 30 crash_save_cpu(regs, cpu); 31 cpu_set(cpu, cpus_in_crash); 32 33 while (!atomic_read(&kexec_ready_to_reboot)) 34 cpu_relax(); 35 relocated_kexec_smp_wait(NULL); 36 /* NOTREACHED */ 37 } 38 39 static void crash_kexec_prepare_cpus(void) 40 { 41 unsigned int msecs; 42 43 unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ 44 45 dump_send_ipi(crash_shutdown_secondary); 46 smp_wmb(); 47 48 /* 49 * The crash CPU sends an IPI and wait for other CPUs to 50 * respond. Delay of at least 10 seconds. 51 */ 52 pr_emerg("Sending IPI to other cpus...\n"); 53 msecs = 10000; 54 while ((cpus_weight(cpus_in_crash) < ncpus) && (--msecs > 0)) { 55 cpu_relax(); 56 mdelay(1); 57 } 58 } 59 60 #else /* !defined(CONFIG_SMP) */ 61 static void crash_kexec_prepare_cpus(void) {} 62 #endif /* !defined(CONFIG_SMP) */ 63 64 void default_machine_crash_shutdown(struct pt_regs *regs) 65 { 66 local_irq_disable(); 67 crashing_cpu = smp_processor_id(); 68 crash_save_cpu(regs, crashing_cpu); 69 crash_kexec_prepare_cpus(); 70 cpu_set(crashing_cpu, cpus_in_crash); 71 } 72