LXR linux/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. */
  13static int crashing_cpu = -1;
  14static cpumask_t cpus_in_crash = CPU_MASK_NONE;
  15
  16#ifdef CONFIG_SMP
  17static 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 (!cpumask_test_cpu(cpu, &cpus_in_crash))
  29                crash_save_cpu(regs, cpu);
  30        cpumask_set_cpu(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
  38static 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 ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
  54                cpu_relax();
  55                mdelay(1);
  56        }
  57}
  58
  59#else /* !defined(CONFIG_SMP)  */
  60static void crash_kexec_prepare_cpus(void) {}
  61#endif /* !defined(CONFIG_SMP)  */
  62
  63void 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        cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
  70}
  71