arch/mips/kernel/crash.c

   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 }