Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Architecture specific (i386/x86_64) functions for kexec based crash dumps.

 *

 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)

 *

 * Copyright (C) IBM Corporation, 2004. All rights reserved.

 *

 */

#include <linux/init.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/smp.h>

#include <linux/reboot.h>

#include <linux/kexec.h>

#include <linux/delay.h>

#include <linux/elf.h>

#include <linux/elfcore.h>

#include <asm/processor.h>

#include <asm/hardirq.h>

#include <asm/nmi.h>

#include <asm/hw_irq.h>

#include <asm/apic.h>

#include <asm/hpet.h>

#include <linux/kdebug.h>

#include <asm/smp.h>

#ifdef CONFIG_X86_32

#include <mach_ipi.h>

#else

#include <asm/mach_apic.h>

#endif

/* This keeps a track of which one is crashing cpu. */

static int crashing_cpu;

#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)

static atomic_t waiting_for_crash_ipi;

static int crash_nmi_callback(struct notifier_block *self,

                        unsigned long val, void *data)

{

        struct pt_regs *regs;

#ifdef CONFIG_X86_32

        struct pt_regs fixed_regs;

#endif

        int cpu;

        if (val != DIE_NMI_IPI)

                return NOTIFY_OK;

        regs = ((struct die_args *)data)->regs;

        cpu = raw_smp_processor_id();

        /* Don't do anything if this handler is invoked on crashing cpu.

         * Otherwise, system will completely hang. Crashing cpu can get

         * an NMI if system was initially booted with nmi_watchdog parameter.

         */

        if (cpu == crashing_cpu)

                return NOTIFY_STOP;

        local_irq_disable();

#ifdef CONFIG_X86_32

        if (!user_mode_vm(regs)) {

                crash_fixup_ss_esp(&fixed_regs, regs);

                regs = &fixed_regs;

        }

#endif

        crash_save_cpu(regs, cpu);

        disable_local_APIC();

        atomic_dec(&waiting_for_crash_ipi);

        /* Assume hlt works */

        halt();

        for (;;)

                cpu_relax();

        return 1;

}

static void smp_send_nmi_allbutself(void)

{

        cpumask_t mask = cpu_online_map;

        cpu_clear(safe_smp_processor_id(), mask);

        if (!cpus_empty(mask))

                send_IPI_mask(mask, NMI_VECTOR);

}

static struct notifier_block crash_nmi_nb = {

        .notifier_call = crash_nmi_callback,

};

static void nmi_shootdown_cpus(void)

{

        unsigned long msecs;

        atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);

        /* Would it be better to replace the trap vector here? */

        if (register_die_notifier(&crash_nmi_nb))

                return;         /* return what? */

        /* Ensure the new callback function is set before sending

         * out the NMI

         */

        wmb();

        smp_send_nmi_allbutself();

        msecs = 1000; /* Wait at most a second for the other cpus to stop */

        while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {

                mdelay(1);

                msecs--;

        }

        /* Leave the nmi callback set */

        disable_local_APIC();

}

#else

static void nmi_shootdown_cpus(void)

{

        /* There are no cpus to shootdown */

}

#endif

void machine_crash_shutdown(struct pt_regs *regs)

{

        /* This function is only called after the system

         * has panicked or is otherwise in a critical state.

         * The minimum amount of code to allow a kexec'd kernel

         * to run successfully needs to happen here.

         *

         * In practice this means shooting down the other cpus in

         * an SMP system.

         */

        /* The kernel is broken so disable interrupts */

        local_irq_disable();

        /* Make a note of crashing cpu. Will be used in NMI callback.*/

        crashing_cpu = safe_smp_processor_id();

        nmi_shootdown_cpus();

        lapic_shutdown();

#if defined(CONFIG_X86_IO_APIC)

        disable_IO_APIC();

#endif

#ifdef CONFIG_HPET_TIMER

        hpet_disable();

#endif

        crash_save_cpu(regs, safe_smp_processor_id());

}