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/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. */
  14static int crashing_cpu = -1;
  15static cpumask_t cpus_in_crash = CPU_MASK_NONE;
  16
  17#ifdef CONFIG_SMP
  18static 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
  39static 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)  */
  61static void crash_kexec_prepare_cpus(void) {}
  62#endif /* !defined(CONFIG_SMP)  */
  63
  64void 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