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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
#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/processor.h>
#include <asm/cputable.h>
#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/runlatch.h>
#include <asm/smp.h>
unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
EXPORT_SYMBOL(cpuidle_disable);
static int __init powersave_off(char *arg)
{
ppc_md.power_save = NULL;
cpuidle_disable = IDLE_POWERSAVE_OFF;
return 1;
}
__setup("powersave=off", powersave_off);
void arch_cpu_idle(void)
{
ppc64_runlatch_off();
if (ppc_md.power_save) {
ppc_md.power_save();
/*
* Some power_save functions return with
* interrupts enabled, some don't.
*/
if (irqs_disabled())
raw_local_irq_enable();
} else {
raw_local_irq_enable();
/*
* Go into low thread priority and possibly
* low power mode.
*/
HMT_low();
HMT_very_low();
}
HMT_medium();
ppc64_runlatch_on();
}
int powersave_nap;
#ifdef CONFIG_PPC_970_NAP
void power4_idle(void)
{
if (!cpu_has_feature(CPU_FTR_CAN_NAP))
return;
if (!powersave_nap)
return;
if (!prep_irq_for_idle())
return;
if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile(PPC_DSSALL " ; sync" ::: "memory");
power4_idle_nap();
/*
* power4_idle_nap returns with interrupts enabled (soft and hard).
* to our caller with interrupts enabled (soft and hard). Our caller
* can cope with either interrupts disabled or enabled upon return.
*/
}
#endif
#ifdef CONFIG_SYSCTL
/*
* Register the sysctl to set/clear powersave_nap.
*/
static struct ctl_table powersave_nap_ctl_table[] = {
{
.procname = "powersave-nap",
.data = &powersave_nap,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{}
};
static struct ctl_table powersave_nap_sysctl_root[] = {
{
.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