[linux-2.6-block.git] / arch / powerpc / kernel / idle.c

// 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_disable();
	} else {
		/*
		 * 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 int __init
register_powersave_nap_sysctl(void)
{
	register_sysctl("kernel", powersave_nap_ctl_table);

	return 0;
}
__initcall(register_powersave_nap_sysctl);
#endif
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Idle daemon for PowerPC. Idle daemon will handle any action
	4	* that needs to be taken when the system becomes idle.
	5	*
a0652fc9 PM	6	* Originally written by Cort Dougan (cort@cs.nmt.edu).
	7	* Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
	8	* Paul Mackerras and others.
1da177e4 LT	9	*
	10	* iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
	11	*
	12	* Additional shared processor, SMT, and firmware support
	13	* Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
	14	*
a0652fc9	15	* 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
1da177e4 LT	16	*/
1da177e4 LT	17
1da177e4 LT	18	#include <linux/sched.h>
	19	#include <linux/kernel.h>
	20	#include <linux/smp.h>
	21	#include <linux/cpu.h>
1da177e4	22	#include <linux/sysctl.h>
1ad74998	23	#include <linux/tick.h>
1da177e4	24
1da177e4	25	#include <asm/processor.h>
1da177e4 LT	26	#include <asm/cputable.h>
1da177e4 LT	27	#include <asm/time.h>
fd899c0c	28	#include <asm/machdep.h>
ae3a197e	29	#include <asm/runlatch.h>
2249ca9d	30	#include <asm/smp.h>
1da177e4	31
1da177e4	32
771dae81 DD	33	unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
	34	EXPORT_SYMBOL(cpuidle_disable);
	35
302eca18	36	static int __init powersave_off(char *arg)
	37	{
	38	ppc_md.power_save = NULL;
771dae81	39	cpuidle_disable = IDLE_POWERSAVE_OFF;
b793a010	40	return 1;
302eca18	41	}
	42	__setup("powersave=off", powersave_off);
	43
799fef06 TG	44	void arch_cpu_idle(void)
	45	{
	46	ppc64_runlatch_off();
	47
	48	if (ppc_md.power_save) {
	49	ppc_md.power_save();
	50	/*
	51	* Some power_save functions return with
	52	* interrupts enabled, some don't.
	53	*/
89b30987 PZ	54	if (!irqs_disabled())
89b30987 PZ	55	raw_local_irq_disable();
799fef06	56	} else {
799fef06 TG	57	/*
	58	* Go into low thread priority and possibly
	59	* low power mode.
	60	*/
	61	HMT_low();
	62	HMT_very_low();
1da177e4	63	}
799fef06 TG	64
	65	HMT_medium();
	66	ppc64_runlatch_on();
1da177e4 LT	67	}
1da177e4 LT	68
1da177e4 LT	69	int powersave_nap;
1da177e4 LT	70
ed0bc98f NP	71	#ifdef CONFIG_PPC_970_NAP
	72	void power4_idle(void)
	73	{
	74	if (!cpu_has_feature(CPU_FTR_CAN_NAP))
	75	return;
	76
	77	if (!powersave_nap)
	78	return;
	79
	80	if (!prep_irq_for_idle())
	81	return;
	82
	83	if (cpu_has_feature(CPU_FTR_ALTIVEC))
d51f86cf	84	asm volatile(PPC_DSSALL " ; sync" ::: "memory");
ed0bc98f NP	85
	86	power4_idle_nap();
	87
	88	/*
	89	* power4_idle_nap returns with interrupts enabled (soft and hard).
	90	* to our caller with interrupts enabled (soft and hard). Our caller
	91	* can cope with either interrupts disabled or enabled upon return.
	92	*/
	93	}
	94	#endif
	95
1da177e4 LT	96	#ifdef CONFIG_SYSCTL
	97	/*
	98	* Register the sysctl to set/clear powersave_nap.
	99	*/
cc293bf7	100	static struct ctl_table powersave_nap_ctl_table[] = {
1da177e4	101	{
1da177e4 LT	102	.procname = "powersave-nap",
	103	.data = &powersave_nap,
	104	.maxlen = sizeof(int),
	105	.mode = 0644,
6d456111	106	.proc_handler = proc_dointvec,
1da177e4	107	},
1da177e4	108	};
1da177e4 LT	109
	110	static int __init
	111	register_powersave_nap_sysctl(void)
	112	{
bfedee5d	113	register_sysctl("kernel", powersave_nap_ctl_table);
1da177e4 LT	114
	115	return 0;
	116	}
	117	__initcall(register_powersave_nap_sysctl);
	118	#endif