Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Idle daemon for PowerPC.  Idle daemon will handle any action

 * that needs to be taken when the system becomes idle.

 *

 * Originally written by Cort Dougan (cort@cs.nmt.edu).

 * Subsequent 32-bit hacking by Tom Rini, Armin Kuster,

 * Paul Mackerras and others.

 *

 * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>

 *

 * Additional shared processor, SMT, and firmware support

 *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>

 *

 * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/smp.h>

#include <linux/cpu.h>

#include <linux/sysctl.h>

#include <linux/tick.h>

#include <asm/system.h>

#include <asm/processor.h>

#include <asm/cputable.h>

#include <asm/time.h>

#include <asm/machdep.h>

#include <asm/smp.h>

#ifdef CONFIG_HOTPLUG_CPU

/* this is used for software suspend, and that shuts down

 * CPUs even while the system is still booting... */

#define cpu_should_die()        (cpu_is_offline(smp_processor_id()) && \

                                   (system_state == SYSTEM_RUNNING     \

                                 || system_state == SYSTEM_BOOTING))

#else

#define cpu_should_die()        0

#endif

static int __init powersave_off(char *arg)

{

        ppc_md.power_save = NULL;

        return 0;

}

__setup("powersave=off", powersave_off);

/*

 * The body of the idle task.

 */

void cpu_idle(void)

{

        if (ppc_md.idle_loop)

                ppc_md.idle_loop();     /* doesn't return */

        set_thread_flag(TIF_POLLING_NRFLAG);

        while (1) {

                tick_nohz_stop_sched_tick();

                while (!need_resched() && !cpu_should_die()) {

                        ppc64_runlatch_off();

                        if (ppc_md.power_save) {

                                clear_thread_flag(TIF_POLLING_NRFLAG);

                                /*

                                 * smp_mb is so clearing of TIF_POLLING_NRFLAG

                                 * is ordered w.r.t. need_resched() test.

                                 */

                                smp_mb();

                                local_irq_disable();

                                /* check again after disabling irqs */

                                if (!need_resched() && !cpu_should_die())

                                        ppc_md.power_save();

                                local_irq_enable();

                                set_thread_flag(TIF_POLLING_NRFLAG);

                        } else {

                                /*

                                 * Go into low thread priority and possibly

                                 * low power mode.

                                 */

                                HMT_low();

                                HMT_very_low();

                        }

                }

                HMT_medium();

                ppc64_runlatch_on();

                tick_nohz_restart_sched_tick();

                if (cpu_should_die())

                        cpu_die();

                preempt_enable_no_resched();

                schedule();

                preempt_disable();

        }

}

int powersave_nap;

#ifdef CONFIG_SYSCTL

/*

 * Register the sysctl to set/clear powersave_nap.

 */

static ctl_table powersave_nap_ctl_table[]={

        {

                .ctl_name       = KERN_PPC_POWERSAVE_NAP,

                .procname       = "powersave-nap",

                .data           = &powersave_nap,

                .maxlen         = sizeof(int),

                .mode           = 0644,

                .proc_handler   = &proc_dointvec,

        },

        {}

};

static ctl_table powersave_nap_sysctl_root[] = {

        {

                .ctl_name       = CTL_KERN,

                .procname       = "kernel",

                .mode           = 0555,

                .child          = powersave_nap_ctl_table,

        },

        {}

};

static int __init

register_powersave_nap_sysctl(void)

{

        register_sysctl_table(powersave_nap_sysctl_root);

        return 0;

}

__initcall(register_powersave_nap_sysctl);

#endif