sstate.c

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/* sstate.c: System soft state support.
 *
 * Copyright (C) 2007, 2008 David S. Miller <[email protected]>
 */

#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>

#include <asm/hypervisor.h>
#include <asm/spitfire.h>
#include <asm/oplib.h>
#include <asm/head.h>
#include <asm/io.h>

#include "kernel.h"

static int hv_supports_soft_state;

static void do_set_sstate(unsigned long state, const char *msg)
{
    unsigned long err;

    if (!hv_supports_soft_state)
        return;

    err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
    if (err) {
        printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
               "state[%lx] msg[%s], err=%lu\n",
               state, msg, err);
    }
}

static const char booting_msg[32] __attribute__((aligned(32))) =
    "Linux booting";
static const char running_msg[32] __attribute__((aligned(32))) =
    "Linux running";
static const char halting_msg[32] __attribute__((aligned(32))) =
    "Linux halting";
static const char poweroff_msg[32] __attribute__((aligned(32))) =
    "Linux powering off";
static const char rebooting_msg[32] __attribute__((aligned(32))) =
    "Linux rebooting";
static const char panicing_msg[32] __attribute__((aligned(32))) =
    "Linux panicing";

static int sstate_reboot_call(struct notifier_block *np, unsigned long type, void *_unused)
{
    const char *msg;

    switch (type) {
    case SYS_DOWN:
    default:
        msg = rebooting_msg;
        break;

    case SYS_HALT:
        msg = halting_msg;
        break;

    case SYS_POWER_OFF:
        msg = poweroff_msg;
        break;
    }

    do_set_sstate(HV_SOFT_STATE_TRANSITION, msg);

    return NOTIFY_OK;
}

static struct notifier_block sstate_reboot_notifier = {
    .notifier_call = sstate_reboot_call,
};

static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
{
    do_set_sstate(HV_SOFT_STATE_TRANSITION, panicing_msg);

    return NOTIFY_DONE;
}

static struct notifier_block sstate_panic_block = {
    .notifier_call  =   sstate_panic_event,
    .priority   =   INT_MAX,
};

static int __init sstate_init(void)
{
    unsigned long major, minor;

    if (tlb_type != hypervisor)
        return 0;

    major = 1;
    minor = 0;
    if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
        return 0;

    hv_supports_soft_state = 1;

    prom_sun4v_guest_soft_state();

    do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);

    atomic_notifier_chain_register(&panic_notifier_list,
                       &sstate_panic_block);
    register_reboot_notifier(&sstate_reboot_notifier);

    return 0;
}

core_initcall(sstate_init);

static int __init sstate_running(void)
{
    do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
    return 0;
}

late_initcall(sstate_running);