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