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/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 }